Wednesday
June 19, 2013

# Homework Help: Science: Physics

Recent Homework Questions About Physics

physics
Maxwell's equations proved that a. Light is a mechanical phenomena b. Light is a chemical phenomena c. Light is a phenomenal phenomena d. Light is an electromagnetic phenomena I think the answer is either a or d. But I'm pretty sure its d Thank you for any help and ...
Sunday, December 16, 2012 at 10:49am

physics
A block of weight 11 N is placed on a frictionless incline which makes an angle of 240 with the horizontal. Find the acceleration of the block as it slides down the incline.
Sunday, December 16, 2012 at 8:52am

physics
The gravitational field strength at the surface of a certain neutron star is 1.34*10^12 N/kg. What would be the theoretical maximum height of a cylindrical granite column which could support its own weight without crushing when exposed to a field of this magnitude? (density of...
Sunday, December 16, 2012 at 8:19am

physics
The gravitational field strength at the surface of a certain neutron star is 1.34*10^12 N/kg. What would be the theoretical maximum height of a cylindrical granite column which could support its own weight without crushing when exposed to a field of this magnitude? (density of...
Sunday, December 16, 2012 at 8:18am

Physics
A rubber ball is attached to a paddle by a rubber band. The ball is initially moving away from the paddle with a speed of 4.0 m/s. After 0.25 s, the ball is moving toward the paddle with a speed of 3.0 m/s. What is the average acceleration of the ball during that 0.25 s? Give ...
Sunday, December 16, 2012 at 4:22am

Calc and Physics
Damon and Reiny. Thanks for your quick and thorough responses.
Sunday, December 16, 2012 at 2:03am

physics
Each of the following objects has a radius of 0.180 m and a mass of 2.65 kg, and each rotates about an axis through its center (as in the table below) with an angular speed of 41.4 rad/s. Find the magnitude of the angular momentum of each object. a) a hoop ___ kg m/s b) a ...
Saturday, December 15, 2012 at 11:58pm

physics
Each of the following objects has a radius of 0.180 m and a mass of 2.65 kg, and each rotates about an axis through its center (as in the table below) with an angular speed of 41.4 rad/s. Find the magnitude of the angular momentum of each object. a) a hoop ___ kg m/s b) a ...
Saturday, December 15, 2012 at 11:56pm

Physics
A 5.00-grain aspirin tablet has a mass of 320 mg. For how many kilometers would the energy equivalent of this mass power an automobile? Assume 12.75 km/L and a heat of combustion of 3.65x10^7 J/L for the gasoline used in the automobile.
Saturday, December 15, 2012 at 10:42pm

Physics
mass of an unknown sample is 0.240 kg in air and 0.208 kg when in oil of density=800 kg/m^3. Determine volume and density. Is the density 0.240/800?
Saturday, December 15, 2012 at 10:29pm

physics
an empty rubber balloon has mass 0.0120kg, the balloon is filled with helium of density 0.181 kg/m^3. the balloon is spherical w/ radius 0.500m. if the balloon is ties to a vertical string, what is thw tension in the string? density of air 1.29 kg/m^3
Saturday, December 15, 2012 at 9:28pm

Physics
A spaceship at rest in a certain reference frame S is given a speed increment of 0.50c. Relative to its new rest frame, it is then given a further 0.50c increment. This process is continued until its speed with respect to its original frame S exceeds 0.999c. How many ...
Saturday, December 15, 2012 at 8:27pm

college physics
have a couple of questions about my homework and it's due at midnight tonight: 1. On a hot summer day, the temperature of air in Arizona reaches 115°F. What is the speed of sound in air at this temperature? (Enter your answer to four significant figures. The speed of ...
Saturday, December 15, 2012 at 8:11pm

Physics
A rogue chipmunk has been raiding the secrete acorn stash of 3 squirrels. On discovering the perpetrator in the very act they secure him with 3 ropes and attempt to pull him off the limb where he falls to his demise. The first squirrel pulls at an angle of 12 degrees with a ...
Saturday, December 15, 2012 at 7:58pm

Physics
a 4 kg block is being pulled by a string at a constant speed on a surface with coeficient of kinetic friction of .3. If the string is at an angle 45 degrees above the horizontal, what is the magnitude of the force F(also known as the string)?
Saturday, December 15, 2012 at 7:28pm

Physics
a 4 kg block is being pulled by a string at a constant speed on a surface with coeficient of kinetic friction of .3. If the string is at an angle 45 degrees above the horizontal, what is the magnitude of the force F(also known as the string)?
Saturday, December 15, 2012 at 7:24pm

Physics
a 4 kg block is being pulled by a string at a constant speed on a surface with coeficient of kinetic friction of .3. If the string is at an angle 45 degrees above the horizontal, what is the magnitude of the force F(also known as the string)?
Saturday, December 15, 2012 at 7:21pm

physics
a truck with a mass of 2100 kg travels at a constant speed of 75 km/h. (a) What is the magnitude of the truck’s linear momentum? kg·m/s (b) What average force would be required to stop the truck in 7.5 s? does this have to do with f=ma or not? help
Saturday, December 15, 2012 at 6:33pm

Physics
If we intercept an electron having total energy 1533 MeV that came from Vega, which is 26 ly from us, how far in light-years was the trip in the rest frame of the electron? (Answer: 8.7*10^-3 ly)
Saturday, December 15, 2012 at 6:12pm

physics
a girl throws a dart with a speed of 12.4 meters per second. the dart hits the board .32 meters below the height from which it was thrown. how far from the board was the girl?
Saturday, December 15, 2012 at 6:02pm

Physics
A 59-kg person on skis starts from rest down a hill sloped at 36° from the horizontal. The coefficient of friction between the skis and the snow is 0.16. After the skier had been moving for 5.0 s, the friction of the snow suddenly increased and made the net force on the ...
Saturday, December 15, 2012 at 4:59pm

Physics
Five forces act on an object. (1) 63 N at 90° (2) 40 N at 0° (3) 83 N at 270° (4) 40 N at 180° (5) 50 N at 60° What are the magnitude and direction of a sixth force that would produce equilibrium?
Saturday, December 15, 2012 at 4:58pm

Physics
A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.88 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
Saturday, December 15, 2012 at 3:11pm

physics
is2A wedge of mass M fitted with a spring of stiftness k is kept on a smoth hrizontal surface. A rod of mass m is kept on the wedge as shown in the figure. System is in equilibrium. Assuming that all the surfaces are smooth, the potential energy stored in the spring: a) ...
Saturday, December 15, 2012 at 2:14pm

physics
Why might it be hard for the firefighter to hold the hose steady when the water gushes out of the hose? Think about the law of conservation of momentum.
Saturday, December 15, 2012 at 1:44pm

physics
You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 206.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...
Saturday, December 15, 2012 at 12:55pm

physics
hi every one i appreciate help as ineed answer as soon a jetplane discharges a jet at rate of 28kg/s with a velocity of 950 m/s relative to the plane if the forward speed of the plane is 875km/h what is the thrust developped on the plane and the power developed at the jet the ...
Saturday, December 15, 2012 at 11:53am

physics
an air craft of mass 5110 kg flying in level flight at speed of 398 knots air enters the engine is 65 kg/s and the jet speed relative to the air craft is 610 m/s if the lift drag ratio is 10 find accerlation and power and thrust thanks if any one can help i done it but i get a...
Saturday, December 15, 2012 at 11:19am

Physics
Hello I am trying to solve this physics problem related to effusion of gases. The following data is given and I am asked to calculate the rate of effusion The data given; depth/thickness (t) Surface area (A) diffusion coefficient (D) Can someone help me out? The only law ...
Saturday, December 15, 2012 at 7:42am

Physics
Amy age 8 27kg 127cm Bruce age 12 41kg 149cm Both Amy and Bruce are learning gymnastics and having trouble being able to get enough height and time in the air to do a back somersault without the coach spotting them. The coach gives them homework to just focus on jumping ...
Saturday, December 15, 2012 at 12:35am

physics
A 224 g particle is released from rest at point A along the diameter on the inside of a fric- tionless, hemispherical bowl of radius 44 cm. The acceleration of gravity is 9.8 m/s2 .
Friday, December 14, 2012 at 11:39pm

physics
An Alaskan rescue plane traveling 37 m/s drops a package of emergency rations from a height of 149 m to a stranded party of explorers. The acceleration of gravity is 9.8 m/s 2 . Where does the package strike the ground relative to the point directly below where it was released...
Friday, December 14, 2012 at 11:25pm

physics
Someone in a car going past you at the speed of 43 m/s drops a small rock from a height of 1.6 m. How far from the point of the drop will the rock hit the ground? The acceleration due to gravity is 9.8 m/s 2 . Answer in units of m
Friday, December 14, 2012 at 11:24pm

physics
During a baseball game, a batter hits a popup to a ﬁelder 64 m away. The acceleration of gravity is 9.8 m/s 2 . If the ball remains in the air for 6.7 s, how high does it rise? Answer in units of m
Friday, December 14, 2012 at 11:23pm

Physics
A fighter jet is launched from an aircraft carrier with the aid of its own engines and a steam-powered catapult. The thrust of its engines is 3.82 x 105 N. In being launched from rest it moves through a distance of 57.2 m and has a kinetic energy of 5.71 x 107 J at lift-off. ...
Friday, December 14, 2012 at 9:43pm

Physics
A bead slides without friction around a loop- the-loop. The bead is released from a height of 12.9 m from the bottom of the loop-the- loop which has a radius 4 m. The acceleration of gravity is 9.8 m/s2 . A 4m 12.9 m What is its speed at point A ? Answer in units of m/s
Friday, December 14, 2012 at 9:02pm

Physics
Find the work done in stretching the spring. Answer in units of J
Friday, December 14, 2012 at 9:00pm

Physics
The force required to stretch a Hooke’s-law spring varies from 0 N to 70.4 N as we stretch the spring by moving one end 5.35 cm from its unstressed position. Find the force constant of the spring. Answer in units of N/m
Friday, December 14, 2012 at 9:00pm

physics
A 22 g bullet is accelerated in a rifle barrel 43.2 cm long to a speed of 907 m/s. Use the work-energy theorem to find the average force exerted on the bullet while it is being accelerated. Answer in units of N
Friday, December 14, 2012 at 8:58pm

physics
Radio waves of frequency 30 kHz are received at a location 1500 km from a transmitter. The radio reception temporarily “fades” due to destructive interference between the waves travelling parallel to the ground and the waves reflected from a layer (ionosphere) of the...
Friday, December 14, 2012 at 7:07pm

Physics
The drawing shows a skateboarder moving at 6.41 m/s along a horizontal section of a track that is slanted upward by 47.4 ° above the horizontal at its end, which is 0.612 m above the ground. When she leaves the track, she follows the characteristic path of projectile ...
Friday, December 14, 2012 at 6:48pm

Physics
You are trying to lose weight by working out on a rowing machine. Each time you pull the rowing bar (which simulates the "oars") toward you, it moves a distance of 1.32 m in a time of 1.22 s. The readout on the display indicates that the average power you are ...
Friday, December 14, 2012 at 6:01pm

Physics
a 32 kg child stands at the edge of a circular platform that rotates at w=2rad/s about its center. Mass of platform=60kg, radius=2m. The child walks from the rim towards the center. Find the Angular speed when the child reaches a point 0.500 m from the center.
Friday, December 14, 2012 at 4:35pm

physics
The yellow line emitted by a helium discharge tube in the laboratory has a wavelength of 587 nm The same yellow line in the helium spectrum of a star has a measured wavelength of 590 nm. Calculate the speed of the moving star.
Friday, December 14, 2012 at 12:36pm

physics
An audio speaker at a concert emits sound uniformly in all directions at a rate of 100 W. (i) Calculate the sound intensity experienced by a listener at a distance of 8 m from the speaker. The listener moves back from the speaker to protect her hearing. (ii) At what distance ...
Friday, December 14, 2012 at 11:45am

physics
In the figure below, the scale on which the 63 kg physicist stands reads 236 N. How long will the cantaloupe take to reach the floor if the physicist drops it (from rest relative to himself) at a height of 2.1 m above the floor? How would you go about solving this?
Friday, December 14, 2012 at 11:42am

physics
The length of a pipe, closed at one end is is 90 cm. Calculate the frequency of the standing wave. What is the fundamental frequency of the pipe?
Friday, December 14, 2012 at 11:25am

physics
A horizontal slingshot consists of two light, identical springs (with spring constants of 37.7 N/m) and a light cup that holds a 1.37-kg stone. Each spring has an equilibrium length of 50 cm. When the springs are in equilibrium, they line up vertically. Suppose that the cup ...
Friday, December 14, 2012 at 10:27am

physics
A stretched string of length 80 cm has a fundamental frequency of vibration of 400 Hz. What is the speed of the sound wave in the stretched string?
Friday, December 14, 2012 at 9:05am

physics
The sound intensity level at a concert increases from 85 dB to 94 dB when the concert begins. By what factor has the sound intensity increased?
Friday, December 14, 2012 at 8:53am

Physics
Show or prove that tan(θ) = v2/rg
Friday, December 14, 2012 at 8:31am

Physics
the net external force of the propeller of a 4.0 kg model airplane is 9.5 N forward. What is the acceleration of the airplane? Answer in units of m/s^2
Thursday, December 13, 2012 at 10:36pm

physics
A machine part rotates at an angular speed of 0.77 rad/s; its speed is then increased to 1.76 rad/s using an angular acceleration of 0.29 rad/s 2 . Find the angle through which the part rotates before reaching this ﬁnal speed. Answer in units of rad
Thursday, December 13, 2012 at 10:23pm

Physics
Two long, straight, parallel wires carry current in the same direction. If the wires are 24 cm apart and carry currents of 2.0 A and 4.0 A, respectively, find the force per unit length on each wire?
Thursday, December 13, 2012 at 10:02pm

physics
A 443 kg mass is brought close to a second mass of 181 kg on a frictional surface with coeﬃcient of friction 0.5. At what distance will the second mass begin to slide toward the ﬁrst mass? The acceleration of gravity is 9.8 m/s 2 and the value of the universal ...
Thursday, December 13, 2012 at 9:51pm

Fund of programming 1
Write a program that prints out your course schedule for a single week. Here's an example of the output for one day: Monday 9:00 Computer Science 101 Monday 11:00 Physics 201 Monday 2:00 Dance 153
Thursday, December 13, 2012 at 9:42pm

physics
An archer puts a 0.34 kg arrow to the bowstring. An average force of 213.1 N is exerted to draw the string back 1.48 m. The acceleration of gravity is 9.8 m/s 2 . Assuming no frictional loss, with what speed does the arrow leave the bow? Answer in units of m/s
Thursday, December 13, 2012 at 9:38pm

physics
How high does a rocket have to go above the Earth’s surface so that its weight is reduced to 33.7 % of its weight at the Earth’s surface? The radius of the Earth is 6380 km and the universal gravitational constant is 6.67 × 10 −11 N · m 2 /kg 2 . ...
Thursday, December 13, 2012 at 9:33pm

physics
Tom has a mass of 72.2 kg and Sally has a mass of 49.4 kg. Tom and Sally are standing 17.4 m apart on a massless dance ﬂoor. Sally looks up and she sees Tom. She feels an attraction. If the attraction is gravitation, ﬁnd its magnitude. Assume both can be replaced...
Thursday, December 13, 2012 at 9:30pm

physics
A 443 kg mass is brought close to a second mass of 181 kg on a frictional surface with coeﬃcient of friction 0.5. At what distance will the second mass begin to slide toward the ﬁrst mass? The acceleration of gravity is 9.8 m/s 2 and the value of the universal ...
Thursday, December 13, 2012 at 9:29pm

current physics
3 kilo ohms ll 5 kilo ohms = 1.875 kilo ohms
Thursday, December 13, 2012 at 9:13pm

Physics
Two long, straight, parallel wires carry current in the same direction. If the wires are 24 cm apart and carry currents of 2.0 A and 4.0 A, respectively, find the force per unit length on each wire? I'm not really sure how to go about this. I must be spacing or something.
Thursday, December 13, 2012 at 8:53pm

physics
A person walks the path shown below. The total trip consists of four straight-line paths. Path 1 is 80.0 m due east. Path 2 is 250.0 m due south. Path 3 is 130.0 m 30.0° south of west. Path 4 is 190.0 m 60.0° north of west. At the end of the walk, what is the person&#...
Thursday, December 13, 2012 at 8:11pm

physics
A person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of vi = 16 m/s. The cliff is h = 60 m above the water's surface, as shown below. (a) How long does it take for the stone to fall to the water? s (b) With what speed does it strike the...
Thursday, December 13, 2012 at 8:10pm

physics
A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials' boat pulls up next to the spy's boat, both reach the edge of a 4.2 m waterfall. If the spy's speed is 20 m/s and the officials' speed is 24 m/s...
Thursday, December 13, 2012 at 8:10pm

Physics
An arrow is shot straight upward at 55 m/s. a) find the time until the arrow reaches its peak b)how high was the arrow at its peak c)find the total time the arrow is in the air d)what was the velocity of the arrow after 3.5 seconds e)how high was it at 3.5 seconds
Thursday, December 13, 2012 at 8:10pm

physics
A shell is fired from the ground with an initial speed of 1.54 103 m/s at an initial angle of 46° to the horizontal. (a) Neglecting air resistance, find the shell's horizontal range. m (b) Find the amount of time the shell is in motion. s
Thursday, December 13, 2012 at 8:10pm

physics
A place kicker must kick a football from a point 32.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 20.8 m/s at an angle of 53° to the horizontal. (a) By how much does ...
Thursday, December 13, 2012 at 8:09pm

Physics
An arrow is shot straight upward at 55 m/s. a) find the time until the arrow reaches its peak b)how high was the arrow at its peak c)find the total time the arrow is in the air d)what was the velocity of the arrow after 3.5 seconds e)how high was it at 3.5 seconds
Thursday, December 13, 2012 at 8:09pm

Physics
An arrow is shot straight upward at 55 m/s. a) find the time until the arrow reaches its peak b)how high was the arrow at its peak c)find the total time the arrow is in the air d)what was the velocity of the arrow after 3.5 seconds e)how high was it at 3.5 seconds
Thursday, December 13, 2012 at 8:09pm

physics
A river flows due east at 1.50 m/s. A boat crosses the river from the south shore to the north shore by maintaining a constant velocity of 9.2 m/s due north relative to the water. (a) What is the velocity of the boat as viewed by an observer on the shore? m/s at ° east of ...
Thursday, December 13, 2012 at 8:09pm

physics
The pilot of an aircraft wishes to fly due west in a 46.8 km/h wind blowing toward the south. The speed of the aircraft in the absence of a wind is 204 km/h. (a) In what direction should the aircraft head? ° north of west (b) What should its speed relative to the ground be...
Thursday, December 13, 2012 at 8:08pm

physics
A hunter wishes to cross a river that is 2.5 km wide and that flows with a speed of 6.0 km/h. The hunter uses a small powerboat that moves at a maximum speed of 9.8 km/h with respect to the water. What is the minimum time necessary for crossing?
Thursday, December 13, 2012 at 8:08pm

physics
A swimmer swims in still water at a speed of 6.83 m/s. He intends to swim directly across a river that has a downstream current of 2.89 m/s. (a) What must the swimmer's direction be?
Thursday, December 13, 2012 at 8:07pm

PHYSICS NEED HELP PLEASE
You need to open a heavy door thats 40 inches wide. Instinctively, you push near the edge thats the farthest from the hinges. If instead, you had pushed at a point only 10 inches in from the hinges, how much harder would you have had to push to open the door at the same speed...
Thursday, December 13, 2012 at 7:50pm

physics
An electron is accelerated from rest to a velocity of 2.0x10^7 m/s. a) if the electron travelled 0.10m while it was being accelerated, what was its acceleration? b)How long did the electron take to attain its final velocity? Please correct me if I'm wrong but I believe the...
Thursday, December 13, 2012 at 7:31pm

A crowbar lever , with a 3 inch long nail remover connected to a 20inch handle. If you push down on the handle end with a force of 40 N, what force is available to remove a nail? HINT: a Crowbar isnt all that different from a seesaw, except the pivot is far off center.
Thursday, December 13, 2012 at 7:30pm

You need to open a heavy door thats 40 inches wide. Instinctively, you push near the edge thats the farthest from the hinges. If instead, you had pushed at a point only 10 inches in from the hinges, how much harder would you have had to push to open the door at the same speed...
Thursday, December 13, 2012 at 7:28pm

physics
a car of mass 12,000 kjg is moving at 40m/s along a strong road. The driver brakes and the car goes 800 meters before stopping. What was the magnitude of the average force of friction (inN) between tires and road?
Thursday, December 13, 2012 at 6:53pm

Suppose a revolving door at the bamk is spinning around once every 5 seconds. As you walk through, you push on the door for 2 seconds, which increases the rotational speed so that it rotates once a second. What was the rotational acceleration due to your push?
Thursday, December 13, 2012 at 6:31pm

Physics
How much work is done to the wagon by the girl pulling her brother shown in Figure 4.16, if she travels 25 m? F= (50N), 30 DEGREES ANGLE
Thursday, December 13, 2012 at 6:27pm

Physics
A crowbar lever , with a 3 inch long nail remover connected to a 20inch handle. If you push down on the handle end with a force of 40 N, what force is available to remove a nail? HINT: a Crowbar isnt all that different from a seesaw, except the pivot is far off center.
Thursday, December 13, 2012 at 6:21pm

Physics
You need to open a heavy door thats 40 inches wide. Instinctively, you push near the edge thats the farthest from the hinges. If instead, you had pushed at a point only 10 inches in from the hinges, how much harder would you have had to push to open the door at the same speed...
Thursday, December 13, 2012 at 6:20pm

Physics help!
Suppose a revolving door at the bamk is spinning around once every 5 seconds. As you walk through, you push on the door for 2 seconds, which increases the rotational speed so that it rotates once a second. What was the rotational acceleration due to your push?
Thursday, December 13, 2012 at 6:19pm

univ. physics
A heat pump has a coefficient of performance of 4.5. If the heat pump absorbs 46.1 cal of heat from the cold outdoors in each cycle, what is the amount of heat expelled to the warm indoors? (in cal)
Thursday, December 13, 2012 at 5:21pm

physics
A cup of coffee is on a table in an airplane flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.100 . Suddenly, the plane accelerates forward, its altitude remaining constant. What is the maximum ...
Thursday, December 13, 2012 at 1:51pm

Physics
A sound wave is traveling in warm air when it hits a layer of cold, dense air. If the sound wave hits the cold air interface at an angle of 23 degree angle, what is the angle of refraction? Assume that the cold air temperature is -10 degrees C and the warm air temperature is +...
Thursday, December 13, 2012 at 12:28pm

physics
A particular guitar string is supposed to vibrate at 210Hz , but it is measured to vibrate at 220Hz By what percent should the tension in the string be changed to correct the frequency?
Thursday, December 13, 2012 at 12:24pm

Physics
a bike passes a lamp post at the crest of hill at 4.5 m/s. she accelerates down the hill at the rate of 0.04 m/s squared for 12 seconds. how far does she move down the hill during this time ?
Thursday, December 13, 2012 at 10:53am

Physics
a hockey player accelerates a puck (m=.167 kg) from rest to a velocity of 50 m/s in 0.0121 sec. Determine the acceleration of the p7uck and the force applied by the hockey stick to the puck. Neglect resistance forces.
Thursday, December 13, 2012 at 10:52am

physics
Two particles are fixed on an x axis. Particle 1 of charge 47.9 μC is located at x = -5.87 cm; particle 2 of charge Q is located at x = 32.3 cm. Particle 3 of charge magnitude 52.8 μC is released from rest on the y axis at y = 15.1 cm. What is the value of Q if the ...
Thursday, December 13, 2012 at 10:47am

physics
Imagine that a new asteroid is discovered in the solar system with a circular orbit and an orbital period of 7 years. What is the average distance of this object from the Sun in Earth units?
Thursday, December 13, 2012 at 2:30am

physics
A baby sitter pushing a stroller starts from rest and accelerates uniformly at a rate of 0.770 m/s 2 . What is the velocity of the stroller after it has traveled 5.94 m? Answer in units of m/s
Thursday, December 13, 2012 at 2:28am

physics
A certain car is capable of accelerating at a uniform rate of 0.84 m/s 2 . What is the magnitude of the car’s displacement as it accelerates uniformly from a speed of 84 km/h to one of 97 km/h? Answer in units of m
Thursday, December 13, 2012 at 2:18am

physics
10 people,each of mass 70 kg, stand on a boat with a mass of 1000 kg. they jump off one end of the boat with velocity 1 m/s relative to the boat. the boat rolls in the opposite direction without friction. a what is the final velocity of the boat if all the people jump at the ...
Thursday, December 13, 2012 at 12:00am

physics
The flywheel of an engine has a moment of inertia of 24 kg*m^2. a) if the radius of the wheel is 0.6m, what force is required to accelerate the wheel from rest to an angular velocity of 300 rpm in 6 seconds? b) how many turns does it make during this time?
Wednesday, December 12, 2012 at 11:57pm

physics
The flywheel of an engine has a moment of inertia of 24 kg*m^2. a) if the radius of the wheel is 0.6m, what force is required to accelerate the wheel from rest to an angular velocity of 300 rpm in 6 seconds? b) how many turns does it make during this time?
Wednesday, December 12, 2012 at 11:57pm

Two identical guitar strings are stretched with the same tension between supports that are not the same distance apart. The fundamental frequency of the higher-pitched string is 400Hz, and the speed of transverse waves in both wires is 200 m/s. How much longer is the lower-...
Wednesday, December 12, 2012 at 11:36pm

Physics
There are two polarizing filters that are out of alignment by 30 degrees. If the light of intensity 1.00 W/m^2 and initially polarized half-way between the two filters passes through the two filters, what is the intensity of the transmitted light? I know the answer is 0.700 W/...
Wednesday, December 12, 2012 at 11:12pm

Physics
A rain cloud contains 2.72 × 10^7 kg of water vapor. The acceleration of gravity is 9.81 m/s^2. How long would it take for a 3.79 kW pump to raise the same amount of water to the cloud’s altitude of 1.85 km? Answer in units of s
Wednesday, December 12, 2012 at 11:11pm

physics
how tall must a water filled manometer be to measure blood pressure as high as 300 mm Hg? what do i use for pressure, density and height?
Wednesday, December 12, 2012 at 11:09pm

physics
what is meant by isolatedsystem?
Wednesday, December 12, 2012 at 10:54pm

Physics
A 4.2 × 10^3 kg car accelerates from rest at the top of a driveway that is sloped at an angle of 18.4◦ with the horizontal. An average frictional force of 4.1×10^3 N impedes the car’s motion so that the car’s speed at the bottom of the driveway is 4...
Wednesday, December 12, 2012 at 10:11pm

Two identical guitar strings are stretched with the same tension between supports that are not the same distance apart. The fundamental frequency of the higher-pitched string is 400Hz, and the speed of transverse waves in both wires is 200 m/s. How much longer is the lower-...
Wednesday, December 12, 2012 at 9:50pm

Physics
What is the net vertical force on this balloon if it is let go? Mass of the rubber 1.50g. Ignore the volume of rubber
Wednesday, December 12, 2012 at 9:32pm

Physics
What is the net vertical force on this balloon if it is let go? The mass of the rubber in the balloon is 1.50g. Ignore the volume of rubber.
Wednesday, December 12, 2012 at 9:30pm

Physics
How much work must be done to increase the speed of an electron (a) from 0.18c to 0.19c and (b) from 0.98c to 0.99c? Note that the speed increase is 0.01c in both cases.
Wednesday, December 12, 2012 at 9:30pm

physics
a boat of mass 90 kg is floating in still water a body of mass 30 kg walks from the stern to the boat the length of the boat is 3m. calculate the distance through which the boat move.
Wednesday, December 12, 2012 at 9:26pm

physics
A stone is thrown upward with a speed of 20 m/s. It is caught on its way down at a point 5.0 m above where it is thrown. A) How fast was it going when it was caught? B) how long did the trip take?
Wednesday, December 12, 2012 at 8:30pm

Physics
A motorist travels 1600 m at 80 m/s and 750 m at 100 m/s. What is the average speed of the motorist for this trip.
Wednesday, December 12, 2012 at 8:20pm

Physics HW ...HELP!!
Two identical guitar strings are stretched with the same tension between supports that are not the same distance apart. The fundamental frequency of the higher-pitched string is 400Hz, and the speed of transverse waves in both wires is 200 m/s. How much longer is the lower-...
Wednesday, December 12, 2012 at 7:59pm

Physics
What is the momentum of a two-particle system composed of a 1400 kg car moving east at 90 m/s and a second 900 kg car moving west at 95 m/s? Let east be the positive direction.
Wednesday, December 12, 2012 at 7:50pm

physics
A 6.1 kg bowling ball is lifted 2.4 m into a storage rack. The acceleration of gravity is 9.8 m/s 2 . Calculate the increase in the ball’s potential energy. Answer in units of J
Wednesday, December 12, 2012 at 7:43pm

Physics
When a load of 0.97 106 N is placed on a battleship, the ship sinks only 3.0 cm in the water. Estimate the cross-sectional area of the ship at water level. (The density of sea water is 1.025 103 kg/m3.)
Wednesday, December 12, 2012 at 7:10pm

Physics
A pipe contains water at 4.80 105 Pa above atmospheric pressure. If you patch a 3.55 mm diameter hole in the pipe with a piece of bubble gum, how much force must it be able to withstand?
Wednesday, December 12, 2012 at 7:10pm

Physics
A mountain climber, in the process of crossing between two cliffs by a rope, pauses to rest. She weighs 554 N. As the drawing shows, she is closer to the left cliff than to the right cliff, with the result that the tensions in the left and right sides of the rope are not the ...
Wednesday, December 12, 2012 at 6:05pm

physics
A woman stands on a scale in a moving elevator. Her mass is 69.1 kg, and the combined mass of the elevator and scale is an additional 734 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force of 9430 N. What does ...
Wednesday, December 12, 2012 at 6:04pm

Physics
A rocket blasts off from rest and attains a speed of 42.2 m/s in 10.9 s. An astronaut has a mass of 63.8 kg. What is the astronaut's apparent weight during takeoff?
Wednesday, December 12, 2012 at 6:04pm

Physics
A student is skateboarding down a ramp that is 8.81 m long and inclined at 27.3 ° with respect to the horizontal. The initial speed of the skateboarder at the top of the ramp is 2.58 m/s. Neglect friction and find the speed at the bottom of the ramp.
Wednesday, December 12, 2012 at 6:03pm

Physics
A car (m = 1510 kg) is parked on a road that rises 12.6 ° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires?
Wednesday, December 12, 2012 at 6:03pm

Physics
Chapter 4, Problem 36 Incorrect. A 77.2-kg person stands on a scale in an elevator. What is the apparent weight when the elevator is (a) accelerating upward with an acceleration of 1.66 m/s2, (b) moving upward at a constant speed, and (c) accelerating downward with an ...
Wednesday, December 12, 2012 at 6:02pm

physics
A neutron star has a mass of 1.27 × 1030 kg (about the mass of our sun) and a radius of 6.47 × 103 m. Suppose an object falls from rest near the surface of such a star. How fast would it be moving after it had fallen a distance of 0.0086 m? (Assume that the ...
Wednesday, December 12, 2012 at 5:50pm

Physics
(a) Calculate the magnitude of the gravitational force exerted on a 430-kg satellite that is a distance of 2.81 times earth radii from the center of the earth. (b) What is the magnitude of the gravitational force exerted on the earth by the satellite? (c) Determine the ...
Wednesday, December 12, 2012 at 4:51pm

Physics
A capacitor has a capacitance of 55 pF. In the charging process electrons are removed from one ate and placed on the other plate. When the potential difference between the plates is 5.3 v how many electrons have been transferred?
Wednesday, December 12, 2012 at 4:41pm

Physics
An organ pipe open at one end has a length of 60 cm. If the speed of sound in air is 340 m/s, what is the lowest frequency produced by the organ pipe? A) 141.5 Hz B) 283 Hz C) 70.8 Hz D) 610 Hz E) 305 Hz
Wednesday, December 12, 2012 at 3:14pm

physics
the magnification caused by a convex lens is represented by Hi/Ho, where hi is the height of the image and ho is the height of the object. Using that ratio, show that the magnification caused by a convex lens is equal to di/do(ratio of the image distance to the object distance.
Wednesday, December 12, 2012 at 1:06pm

physics
Haloke does 179 J of work lifting himself 0.296 m. What is Haloke's mass?
Wednesday, December 12, 2012 at 1:00pm

physics
An object is placed 3cm in front of a diverging lens of focal length of 6cm. the heihgt of the object is 1.5 cm. calculate the image distance and height
Wednesday, December 12, 2012 at 11:52am

college physics
You are on a ladder painting your house. You accidentally drop a bucket of paint weighing 10lb from a height of 17ft. With what speed do the paint and bucket hit the rose bushes below? Would it be different if you dropped your paintbrush weighing 1/2 lb instead? b) what color ...
Wednesday, December 12, 2012 at 11:48am

Physics
If you throw a ball straight upward at a speed of 24 m/s, how long will it take to reach zero speed? How long will it take to return to its starting point? How fast will it be going when it returns to its starting point?
Wednesday, December 12, 2012 at 11:41am

Physics
A long wire carries a current of 20 A along the directed axis of a long solenoid. The field due to the solenoid is 4 mT. Find the field at a point 3 mm from the solenoid axis.
Wednesday, December 12, 2012 at 10:25am

Physics
A long wire carries a current of 20 A along the directed axis of a long solenoid. The field due to the solenoid is 4 mT. Find the field at a point 3 mm from the solenoid axis.
Wednesday, December 12, 2012 at 10:25am

physics
It takes 2.5 J of energy to stretch a helical spring by 15 cm. Determine the spring constant.
Wednesday, December 12, 2012 at 8:53am

physics
A rod of length L = 1.2 m pivots freely about one end. The rod is held horizontally and released, with no intial velocity. Find the angular velocity of the rod as it passes through the vertical orientation. (Use conservation of energy. The rotational inertia of a rod like this...
Wednesday, December 12, 2012 at 1:37am

physics
calculate the value of g at a height of 3600 km above the surface of the earth?
Wednesday, December 12, 2012 at 12:39am

Physics
Rather than taking the stairs, Javier gets from the second floor of his house to the first floor by sliding down the banister that is inclined at an angle of 30.0 degrees to the horizontal. If Javier has a mass of 49.1 kg and the coefficient of kinetic friction between Javier ...
Tuesday, December 11, 2012 at 11:52pm

Physics
A server at a diner slides a 0.521 kg root beer from the end of the counter to a thirsty customer. A force of friction of 1.32 N brings the drink to a stop right in front of the customer. What is the coefficient of kinetic friction between the glass and the counter?
Tuesday, December 11, 2012 at 11:25pm

physics
A small girl and boy take a sled up to the top of a snow covered slope which is inclined 30 degrees above the horizontal. The girl, boy and the sled have a mass of 160 kg. The coefficient of static friction is 0.28 and the coefficient of kinetic friction is 0.14 between the ...
Tuesday, December 11, 2012 at 11:02pm

physics
A small girl and boy take a sled up to the top of a snow covered slope which is inclined 30 degrees above the horizontal. The girl, boy and the sled have a mass of 160 kg. The coefficient of static friction is 0.28 and the coefficient of kinetic friction is 0.14 between the ...
Tuesday, December 11, 2012 at 11:02pm

physics
A large water tank is 18m above the ground. Suppose a pipe with a diameter of 8cm is connected to the tank and leads down to the ground. How fast does the water rush of the piper at ground level? Assume that the tank is open to the atmosphere.
Tuesday, December 11, 2012 at 10:04pm

physics
In another solar system, a 100,000 kg spaceship and a 200,000 kg spaceship are connected by a motionless 90 m long tunnel. The rockets start their engines at the same time, and each produces 50,000 N of thrust in opposing directions. What is the system's angular velocity ...
Tuesday, December 11, 2012 at 9:04pm

physics
A plank with m=0.12 kg and 50cm long has one mass of m1=0.11kg sitting on one end and a m2=0.055kg at the other end. Where should the pivot point be to balance the plank?
Tuesday, December 11, 2012 at 8:07pm

physics
suppose that a seat-belted mother riding in an automobile holds a 10 kg baby in her arms. the automobile crashes and decelerates from 50km/h to 0 in .1 s. what average force would the mother have to exert on the baby to hold it?? do you think she can do this?
Tuesday, December 11, 2012 at 8:05pm

physics
suppose that a seat-belted mother riding in an automobile holds a 10 kg baby in her arms. the automobile crashes and decelerates from 50km/h to 0 in .1 s. what average force would the mother have to exert on the baby to hold it?? do you think she can do this?
Tuesday, December 11, 2012 at 8:05pm

physics
A rule of thumb for automobile collisions against a rigid barrier is that the collision lasts about .11 seconds, for any initial speed and for any model of automobile. accordingly, the deceleration experienced by an automobile during a collision is directly proportional to the...
Tuesday, December 11, 2012 at 8:03pm

college physics
a large cuckoo clock has a pendulum with a period of 1.0 sec. The clock loses 10 min a day. how would you fix it? (Hint: change l) a. Find the length l of the pendulum. b. How much adjustment in l, up or down, is needed?
Tuesday, December 11, 2012 at 7:51pm

PHYSICS
If it take a force of 10,000N to accelerate a car with a mass of 1250KG at a rate of 6m/s^2, what is the force of friction acting against the car?
Tuesday, December 11, 2012 at 7:51pm

PHYSICS
how far will a 1000kg car travel in 10 sec if it is accelerated from rest by a force of 5000N
Tuesday, December 11, 2012 at 7:50pm

Physics
Suppose you put a 100 W light bulb in a container of water and use it to heat the water. How long would it take to raise the temperature of a gallon of water at 25 C to 90C? Please explain!
Tuesday, December 11, 2012 at 7:49pm

Physics
You have a circular table. You measured its radius to be 10 cm with an uncertainty dr =+/- 3mm. The area would be A +/- a cm^2. a. What is A? b. What is a?
Tuesday, December 11, 2012 at 7:47pm

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