Homework Help: Science: Physics

Recent Homework Questions About Physics

physics
If a baseball moving at 96 m/s toward homeplate over a distance of 16 m how much force does it take to make the ball go 50 m from home plate after it is hit?
Sunday, March 10, 2013 at 12:26am

Physics
A boat sets off perpendicular to the bank, to cross a river width of 250m. The speed of the boat in still water is 3.20ms-1, however there is a current downstream at 1.20ms-1, which puss the boat sideways. a) Find the resultant velocity of the boat. b) Find the total distance ...
Saturday, March 9, 2013 at 10:04pm

physics
a uniform rod 100cm long and weighing 50N is supported on a horizontal position on a fulcrum which weights of 80N and 100N suspended on its ends. compute the position of the fulcrum
Saturday, March 9, 2013 at 9:41pm

Physics
A car with engine trouble slides 85 meters up along a 14 degrees ramp before coming to a stop. If the coefficient of friction between the tires and the road is 0.9, what was the velocity of the car at the bottom of the ramp? I get 32.43 meters / second is this correct?
Saturday, March 9, 2013 at 9:32pm

Physics
A 0.157kg ball is thrown straight up from 1.81m above the ground. Its initial vertical speed is 10.40m/s. A short time later, it hits the ground. Calculate the total work done by the force of gravity during that time.
Saturday, March 9, 2013 at 9:27pm

Physics
A pellet gun is fired straight downward from the edge of a cliff that is 15m above the ground. The pellet strikes the ground with a speed of 27 m/s. How long does it take for the pellet to reach the ground with an initial velocity of 5.9 m/s.
Saturday, March 9, 2013 at 8:41pm

Astronomy - Physics
Finally, we will look at a system that is in an orbit comparable to the Earth to see how the angle that the light strikes the surface and the length of day contribute to the total amount of energy that we receive from the Sun at the two solstices. Recall that the changing ...
Saturday, March 9, 2013 at 7:20pm

Astronomy - Physics
Now, wait until the planet is at the winter solstice (12:00am). a) How many hours of daylight are there on the winter solstice with the inclination at 45 degrees? Use the same criteria for the length of day that you used for the previous question. sunlight-hours = (angle ...
Saturday, March 9, 2013 at 7:19pm

Astronomy - Physics
Now let us consider the length of time that the Sun is visible. Wait until the planet is at the summer solstice (12:00am). a) How many hours of daylight are there on the summer solstice with the inclination at 45 degrees? To estimate the length of day, identify the time when ...
Saturday, March 9, 2013 at 7:18pm

Physics ~please help me~
1.) Two people of the same mass climb the same flight of stairs. The first person climbs the stairs in 25 s; the second person does so in 35 s. a) Which person does more work?Explain b) Which person produces more power?Explain 2.) Lee pushes a 20 kg mass 10 m across a floor ...
Saturday, March 9, 2013 at 5:27pm

physics
Four masses are arranged as shown. They are connected by rigid, massless rods of lengths 0.50 m and d = 0.73 m. What torque must be applied to cause an angular acceleration of 0.63 rad/s2 about the axis shown? 4 kg 3 kg 5 kg 2 kg
Saturday, March 9, 2013 at 4:50pm

physics
You've taken your neighbor's young child to the carnival to ride the rides. She wants to ride The Rocket. Eight rocket-shaped cars hang by chains from the outside edge of a large steel disk. A vertical axle through the center of the ride turns the disk, causing the ...
Saturday, March 9, 2013 at 3:49pm

physics
A toy train rolls around a horizontal 1.0-{\rm m}-diameter track. The coefficient of rolling friction is 0.15. What is the magnitude of the train's angular acceleration after it is released?
Saturday, March 9, 2013 at 3:47pm

Physics
A traffic light is suspended midway across a 60 meter wide street by a cable that is attached to vertical poles on either side of the street. When the traffic light is hung in the middle the cable sags 30 cm. If the light is 1500 kg what should be the minimum tension rating ...
Saturday, March 9, 2013 at 1:50pm

physics
A roller-coaster car has a mass of 1100 kg when fully loaded with passengers. As the car passes over the top of a circular hill of radius 20 m, its speed is not changing. (a) At the top of the hill, what is the normal force (using the negative sign for the downward direction) ...
Saturday, March 9, 2013 at 12:55pm

physics
The density of ice is 917 kg/m3, and the density of sea water is 1025 kg/m3. As shown is the figure, a polar bear climbs onto a piece of ice, which has a volume of 5.75 m3, and is floating in sea water. a) What is the mass of the piece of ice? b) What is the mass of the ...
Saturday, March 9, 2013 at 11:43am

Physics
A 3.23 kg ball is attached to a ceiling by a 1.31 m long string. The height of the room is 5.75 m. What is the gravitational potential energy of the ball relative to the ceiling? What is the gravitational potential energy of the ball relative to the floor? What is the ...
Saturday, March 9, 2013 at 11:08am

Physics
If the spring is compressed a distance of 0.144 m and the gun fired vertically as shown, the gun can launch a 18.5g projectile from rest to a maximum height of 19.5 m above the starting point of the projectile. Neglecting all resistive forces, determine the spring constant ...
Saturday, March 9, 2013 at 11:01am

Physics
A 71.1 kg man steps out a window and falls (from rest) 1.24 m to a sidewalk. What is his speed just before his feet strike the pavement? If the man falls with his knees and ankles locked, the only cushion for his fall is a 0.500 cm give in the pads of his feet. Calculate the ...
Saturday, March 9, 2013 at 3:23am

Physics
A stationary bomb of 10kg mass explodes into 3 fragments. two of these parts having mass 4kg and 2kg,fly apart perpendicular to each other with a velocity of 2ms-1 and 3ms-1.find magnitude and direction of 3rd part.
Saturday, March 9, 2013 at 1:45am

Physics
a boat crosses a 2 km wide river by starting out at the south shore and heading directly for the north shore if the river flows at 0.8 m/s and the boat can go at 1.4 m/s in still water, where on the opposite shore will the boat land?
Saturday, March 9, 2013 at 1:41am

Physics
A ball of 0.5kg mass hits a wall at an angle of 30° and is then reflected making an angle of 90° with its original direction. if the duration of contact between the ball and the wall is 0.1s,calculate the force exerted on the wall. the initial and final velocities of ...
Saturday, March 9, 2013 at 1:25am

Lang. Arts
He became famous for his theories of (22) relativity and won the 1921 Nobel Prize for physics. relativity and won A.relativity, and won B.relativity and, won C.relativity, and, won D.no error I think it is D...?
Friday, March 8, 2013 at 10:16pm

Lang. Arts
Einstein (21) was however also publishing papers in physics. was however also A.was, however, also B.was however, also C.was, however also D.no error I think it is A...?
Friday, March 8, 2013 at 10:07pm

physics
A 71.1 kg man steps out a window and falls (from rest) 1.24 m to a sidewalk. What is his speed just before his feet strike the pavement?
Friday, March 8, 2013 at 9:46pm

physics
A 50.7 kg student climbs a 6.35 m long rope and stops at the top. What must her average speed be in order to match the power output of a 130 W lightbulb
Friday, March 8, 2013 at 9:43pm

Physics
Jane weighs 150 lbs and bob weighs 220 , they try skydiving , if they jump at the same time , who reach the ground first /
Friday, March 8, 2013 at 7:16pm

physics
Two identical +9.5uF point charges are initially 3.5cm from each other. If they are released at the same instant from rest, how fast will each be moving when they are very far away from each other? Assume they have identical masses of 2.0mg (P.s. I am not in calculus) so the ...
Friday, March 8, 2013 at 6:50pm

physics
A C1= 2.50uF capacitor is charged to 862 V and a C2= 6.80uF capacitor is charged to 660 V . These capacitors are then disconnected from their batteries. Next the positive plates are connected to each other and the negative plates are connected to each other. What will be the ...
Friday, March 8, 2013 at 6:32pm

physics
White light illuminates an oil film on water. Viewing it directly from above, it looks red. Assume that the reflected red light has a wavelength of 615 nm in air, and that the oil has a thickness of 2.430e-7 m. What is the refractive index of the oil? Assume that the ...
Friday, March 8, 2013 at 4:50pm

physics
An electromagnetic wave has an electric field strength of 145 V/m at a point P in space at time t. (a) What is the electric field energy density at P? (b) A parallel-plate capacitor whose plates have area 0.110 m2 has a uniform electric field between its plates with the same ...
Friday, March 8, 2013 at 4:48pm

physics
A rigid container holds hydrogen gas at a pressure of 3.0 atm and a temperature of 20 degrees Celsius. What will the pressure be if the temperature is lowered to -33 degrees Celsius? Please give your final answer in atm. Answer
Friday, March 8, 2013 at 4:14pm

Marine Physics
A cylindrical container is 30cm in diameter. If is filled at rest by 20 cm of fresh water, and then spun at 30 rpm. after state of solid body rotation is achieved, what is the difference in level between the rim and the center
Friday, March 8, 2013 at 3:58pm

physics
You launch a model rocket up into the sky. Right after launch the rocket is accelerating upwards at 10 m/s2. What is the magnitude of the net force in Newtons on the rocket if the rocket has a mass of 0.1 kg?
Friday, March 8, 2013 at 3:56pm

college physics
small one-cylinder gasoline engines sometimes use a device called a magneto to supply current to the spark plug. A permanent magnet is attached to the flywheel, and a stationary coil is mounted adjacent to it. Explain how this device is able to generate current. What ha[[ens ...
Friday, March 8, 2013 at 3:22pm

physics
A constant force of 46.3 N, directed at 28.7 degrees from horizontal, pulls a mass of 14.7 kg horizontally a distance of 3.09 m. Calculate the work done by the force.
Friday, March 8, 2013 at 2:08pm

Physics
A model rocket has a mass of 3.00 kg. It is fired so that when it is 220 m above the ground it is travelling vertically upward at 165 m/s. At that point its fuel runs out so that the rest of its flight is without power. Assume that the effect of air friction is negligible and ...
Friday, March 8, 2013 at 1:57pm

physics
The figure gives the speed v versus time t for a 0.189 kg object of radius 6.42 cm that rolls smoothly down a 39.5° ramp. What is the rotational inertia of the object? im confused, how does kinetic energy relate to inertia? do i use the equations for torque?
Friday, March 8, 2013 at 1:57pm

Physics
A net force of 5.75 * 103 N [180degree] acts on a mass of 23.0 kg. If, while the force acts, the mass travels through a displacement of 360 m [210 degree], what work did the net force do on the object? Into what form of energy was this work transferred?
Friday, March 8, 2013 at 1:50pm

Physics
an airplane is flying in a horizontal of radius 1.0 km what must be the speed of the plane if the pilot is to experience a centripetal acceleration three times that of gravity.
Friday, March 8, 2013 at 12:32pm

Physics
Given an acceleration of 0.6 m/s/s, on the surface of an asteroid with a radius of 1200 meters, find the mass of the asteroid.
Friday, March 8, 2013 at 12:14pm

Physics
A fast-moving superhero in a comic book runs around a circular, 70-m-diameter track five and a half times (ending up directly opposite her starting point) in 3.0s. What is her angular speed, in rad/s?
Friday, March 8, 2013 at 11:26am

physics
The pendulum shown right has a mass of 0.26 kg and moves to the right from point B to point A. At point B the speed of the mass is 3.2 m/s. (i) What is the change in the gravitational potential energy in the motion from B to A? (ii) What is the mass speed at point A? (iii) If...
Friday, March 8, 2013 at 9:40am

Physics
A 7.00 x 10 -5 H solenoid is constructed by wrapping 66 turns of wire around a cylinder with a cross-sectional area of 6.2 x 10-4 m2. When the solenoid is shortened by squeezing the turns closer together, the inductance increases to 8.40 x 10-5 H. Determine the change in the ...
Thursday, March 7, 2013 at 9:54pm

Physics
During a 74-ms interval, a change in the current in a primary coil occurs. This change leads to the appearance of a 4.6-mA current in a nearby secondary coil. The secondary coil is part of a circuit in which the resistance is 12 Ù. The mutual inductance between the two ...
Thursday, March 7, 2013 at 9:37pm

Physics
A flat circular coil with 192 turns, a radius of 2.35 x 10-2 m, and a resistance of 0.359 Ù is exposed to an external magnetic field that is directed perpendicular to the plane of the coil. The magnitude of the external magnetic field is changing at a rate of ÄB/&...
Thursday, March 7, 2013 at 9:14pm

Physics
Two flat surfaces are exposed to a uniform, horizontal magnetic field of magnitude 0.79 T. When viewed edge-on, the first surface is tilted at an angle of 26° from the horizontal, and a net magnetic flux of 9.2 x 10-4 Wb passes through it. The same net magnetic flux passes...
Thursday, March 7, 2013 at 8:47pm

Physics
A 50.0g ball of clay traveling east at 3.00 m/s collides and sticks together with a 50.0g ball of clay traveling north at 3.50m/s. What is the speed and direction of the resulting ball of clay?
Thursday, March 7, 2013 at 8:42pm

Physics
A 90kg stuntman falls from a building that is 80 meters tall. (Vo = 0)Fortunately, the stuntman is attached to a cable that is wrapped around a flywheel (massive spool), with a radius of 0.5m. If the man takes 8 seconds to reach the ground: (a) what is the moment of inertia of...
Thursday, March 7, 2013 at 8:13pm

physics
A 90kg stuntman falls from a building that is 80 meters tall. (Vo = 0) Fortunately, the stuntman is attached to a cable that is wrapped around a flywheel (massive spool), with a radius of 0.5m. If the man takes 8 seconds to reach the ground, (a) what is the moment of inertia ...
Thursday, March 7, 2013 at 7:34pm

Physics
A ball of mass 0.3 kg, initially at rest, is projected from ground level toward a wall that is 27.0 m away. The ball's velocity the moment it is projected is 75.0 m/s at 60° relative to the horizontal, and the wall is 11.0 m high. During its flight, the ball impacts ...
Thursday, March 7, 2013 at 7:15pm

math
A textbook store sold a combined total of 315 physics and chemistry textbooks in a week. The number of physics textbooks sold was two times the number of chemistry textbooks sold. How many textbooks of each type were sold?
Thursday, March 7, 2013 at 5:44pm

Physics-VASTS
The Mass Budget: Mars Reconnaissance Orbiter Repair Mission Operational Concept Math Problem: The Mars Reconnaissance Orbiter (MRO) has encountered a failure in its High Resolution Imaging Science Experiment (HiRISE) camera. Mission Case: As the HiRISE camera contains the ...
Thursday, March 7, 2013 at 4:29pm

Physics II
A 51.0 g sample of a conducting material is all that is available. The resistivity of the material is measured to be 12 10-8 · m, and the density is 7.67 g/cm3. The material is to be shaped into a solid cylindrical wire that has a total resistance of 1.5 . What length ...
Thursday, March 7, 2013 at 4:08pm

Physics
Periodic waves spread out over the surface of a lake where two women, Jenny and Melissa, are fishing in separate boats 102 meters apart. Each woman's boat bobs up and down 19/min. At a time when Jenny's boat is at a crest, Melissa's boat is at its lowest point, and...
Thursday, March 7, 2013 at 3:42pm

college physics
A long, straight, cylindrical wire of radius R carries a current uniformly distributed over its cross section. 1. At what location is the magnetic field produced by this current equal to quarter of its largest value? Consider points inside the wire. 2.At what location is the ...
Thursday, March 7, 2013 at 3:36pm

Physics
A 1.2kg box on a table slides through a displacement of d is equals to 2m a frictional force fx =0.5N Wat is the initial speed of the box
Thursday, March 7, 2013 at 2:22pm

Physics
What does a simple pendulum travel through at the lowest point during its period?
Thursday, March 7, 2013 at 2:14pm

Physics
A roof tile of 0.2kg drops 10m from the top of the building to the ground if a tile falls with a uniform velocity calculate its k.E as it stricks the ground using kinematic principle
Thursday, March 7, 2013 at 2:07pm

Physics
A thundercloud has an electric charge of 43.2 C near the top of the cloud and -38.7 C near the bottom of the cloud. The magnitude of the electric force between these two charges is 3.95x10^6 N. What is the average separation between these charges? (kc=8.99×10^9 N • ...
Thursday, March 7, 2013 at 1:56pm

physics
A 36 cm long copper wire carries a current of 6.0 A and weighs 0.45 N. A certain magnetic field is strong enough to balance the force of gravity on the wire. What is the strength of the magnetic field?
Thursday, March 7, 2013 at 12:58pm

physics,dynamics
The acceleration of a particle along a straight line is defined by a = (2t - 9) m/s2, where t is in seconds. At t = 0, s = 1 m and v = 10 m/s. When t = 9 s, determine (a) the particle’s position, (b) the total distance traveled, and (c) the velocity.
Thursday, March 7, 2013 at 12:41pm

physics/math
A spherical raindrop of mass 0.0108 g and radius 1.37 mm falls from a cloud that is at a height of 1165 m above the ground. Assume the drag coefficient for the raindrop is 0.60 and the density of the air is 1.3 kg/m3. What is the raindrop's terminal speed? What would be ...
Thursday, March 7, 2013 at 12:01pm

Physics/math
A block with mass m = 16.1 kg slides down an inclined plane of slope angle 24.3o with a constant velocity. It is then projected up the same plane with an initial speed 3.35 m/s. How far up the incline will the block move before coming to rest?
Thursday, March 7, 2013 at 11:59am

Physics/mats
Two blocks with masses m1 = 1.40 kg and m2 = 3.00 kg are connected by a massless string, as shown in the Figure. They are released from rest. The coefficent of kinetic friction between the upper block and the surface is 0.390.In the figure m1 is on top of a horizontal table ...
Thursday, March 7, 2013 at 11:58am

physics
A 445 g sample of ice at -58CENTIGRADE iS HEated until its temparature reaches -29 centigrade.find the change in heat contend of the system.
Thursday, March 7, 2013 at 10:45am

physics
why are water tanks broader at the bottom than at the top
Thursday, March 7, 2013 at 9:59am

physics
I child with a mass of 20kg,hops on a merry go round with moment of intertia of 1000kg and radius of 7m.if it takes the child time T to move 360degrees ,relative to the ground at 6m away from the center,what is the angle covered relative to the ground
Thursday, March 7, 2013 at 9:58am

Check my physics
Would you mind checking one of my problems from my physics study guide? I know the answer and just want to make sure I am using the right formula. :) A 78-kg skydiver has a speed of 62 m/s at an altitude of 870 m above the ground. a. Determine the kinetic energy possessed by ...
Thursday, March 7, 2013 at 8:40am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #8: A 20 kg block of ice slides without friction down a long hill. The start ...
Thursday, March 7, 2013 at 8:28am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #7: A 30 kg ball is launched at an angle of 15 degrees and is moving 20 m/s ...
Thursday, March 7, 2013 at 8:26am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #6: A 30 kg kid on rollerskates is moving 1 m/s. His brother pushes him with a...
Thursday, March 7, 2013 at 8:25am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #5: A roller coaster car starts at Point A at a height of 100 m. When it ...
Thursday, March 7, 2013 at 8:24am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #4: What is the increase in thermal energy to a 2000 kg bus and its ...
Thursday, March 7, 2013 at 8:23am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #3: A 30 kg kid on rollerskates is being pushed by his mom with a force of 10 ...
Thursday, March 7, 2013 at 8:22am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #2: Suppose the spring in a pinball machine has a spring contant of k=400 N/m...
Thursday, March 7, 2013 at 8:21am

PHYSICS
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #1: A skier with a mass of 60.0 kg is standing at the top of a snow covered ...
Thursday, March 7, 2013 at 8:20am

physics
A flight attendant pulls her 70 N flight bag a distance of 253 m along a level airport floor at a constant speed. The force she exerts is 40 N at an angle of 53° above the horizontal A) Find the work that she does on the flight bag B) Find the work done by the force of ...
Thursday, March 7, 2013 at 6:22am

physics
. A block weighing 50 lbs is pulled horizontally w/ constant speed, if the coefficient friction between the surfaces in contact is 0.25, how much heat is generated by friction if the body moves a distance of 40 ft
Thursday, March 7, 2013 at 5:13am

Physics
A 4kg mass is pushed with a constant force for 1m then off the edge of the table and lands 7m from the edge of the table. a) What was the force pushing on the mass? b) What is the resultant velocity?
Thursday, March 7, 2013 at 1:49am

Physics
I'd like to know when it is appropriate to use each formula. Im new to studying physics and its seems that there are certain situations when one formula leads to the answer, yet a derivative of that formula that should lead to the answer is incorrect. For example: the ...
Thursday, March 7, 2013 at 1:44am

physics
when inflated, a rubber lifeboat takes the form of rectangular box of dimensions 2mx1.5x40cm. with out any load, it floats. how many 60kg people can it carry before water flows into it? assume that the density of seawater is 1025g/cubic meter.
Thursday, March 7, 2013 at 1:03am

Physics
You launch a model rocket up into the sky. Right after launch the rocket is accelerating upwards at 10~m/s^2. What is the magnitude of the net force in Newtons on the rocket if the rocket has a mass of 0.1 kg?
Thursday, March 7, 2013 at 12:02am

Physics
Calculate the ratio of the drag force on a jet flying at 1049 km/h at an altitude of 10.0 km to the drag force on a prop-driven transport flying at 560 km/h and at an altitude of 5.00 km. The density of air is 0.380 kg/m3 at 10.0 km and 0.670 kg/m3 at 5.00 km. Assume that the ...
Wednesday, March 6, 2013 at 9:17pm

Physics
A block with mass m = 16.1 kg slides down an inclined plane of slope angle 24.3o with a constant velocity. It is then projected up the same plane with an initial speed 3.35 m/s. How far up the incline will the block move before coming to rest?
Wednesday, March 6, 2013 at 9:16pm

Physics
How much heat must be removed when 25 grams of steam at 100°C Is condensed to form liquid water at 100°C?
Wednesday, March 6, 2013 at 9:15pm

Physics
Two blocks with masses m1 = 1.40 kg and m2 = 3.00 kg are connected by a massless string, as shown in the Figure. They are released from rest. The coefficent of kinetic friction between the upper block and the surface is 0.390.In the figure m1 is on top of a horizontal table ...
Wednesday, March 6, 2013 at 9:14pm

Physics
A proton moves eastward in the plane of Earth’s magnetic equator so that its distance from the ground remains constant. What is the speed of the proton if Earth’s magnetic ﬁeld points north and has a magnitude of 5.2 × 10−5 T? The acceleration of ...
Wednesday, March 6, 2013 at 8:29pm

Physics
How much work must be done on a 500-kg car to accelerate it from 29-km/hr to 112-km/hr?
Wednesday, March 6, 2013 at 7:12pm

Physics
You are standing on top of a building that is 75-m high and you throw a 4-kg stone horizontally at a speed of 6.6-m/s. How far from the base of the building will the stone land? (the ground is flat)
Wednesday, March 6, 2013 at 7:11pm

Physics
What must the critical angle be if light transmits from diamond into water?
Wednesday, March 6, 2013 at 7:10pm

Physics
An unknown material is submerged in a fluid with an index of refraction of 1.33. If a ray of light is incident on the block at 45-degrees and the angle of refraction is 30-degrees. What is the index of the unknown material?
Wednesday, March 6, 2013 at 7:09pm

Physics
A ray of light in air has an angle of incidence to the normal of 45° into a piece of glass (1.5). What is the angle of refraction?
Wednesday, March 6, 2013 at 7:08pm

physics
A strong electromagnet produces a uniform field of 1.31 T over a cross-sectional area of 0.195 m2. A coil having 245 turns with a total resistance of 16 is placed around the electro- magnet, and the current in the electromagnet is turned off, reaching zero in 19.3 ms. What ...
Wednesday, March 6, 2013 at 6:58pm

physics
A car with a weight of 5000.0 N is accelerated across a level surface at 2.5 m/s^2. What is the net force acts on the wagon? (g= 9.81 m/s^2)
Wednesday, March 6, 2013 at 6:24pm

Physics
A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?
Wednesday, March 6, 2013 at 5:44pm

Physics
A proton moves eastward in the plane of Earth’s magnetic equator so that its distance from the ground remains constant. What is the speed of the proton if Earth’s magnetic field points north and has a magnitude of 5.2 × 10−5 T? The acceleration of gravity...
Wednesday, March 6, 2013 at 5:00pm

Physics
A racquet ball with mass m = 0.224 kg is moving toward the wall at v = 14.8 m/s and at an angle of è = 27° with respect to the horizontal. The ball makes a perfectly elastic collision with the solid, frictionless wall and rebounds at the same angle with respect to ...
Wednesday, March 6, 2013 at 4:49pm

Physics
An object with mass 5.0 kg is attached to a spring with spring stiffness constant 192 N/m and is executing simple harmonic motion. When the object is 0.35 m from its equilibrium position, it is moving with a speed of 0.02 m/s. Calculate the amplitude of the motion.
Wednesday, March 6, 2013 at 4:21pm

physics
calculate the current in the secondary coil when the current in the primary coil is 0.50 A. there are 200 turns in the primary coil and 3000 turns on the secondary. the input voltage is 55 v
Wednesday, March 6, 2013 at 3:54pm

Physics
Two parallel plate capacitor of capacitant, two microfarad &three microfarad are connec ted in parallel and d combination is 50V direct current. Draw d circuit diagram of arrangement and determine d following (i)charge on either plate of each capacity. (ii)p.d across d each ...
Wednesday, March 6, 2013 at 3:22pm

Physics
A capacitor of a capacitant is subjected to 2000V of p.d across its terminal. Calculate the energy stored in the capacitor?
Wednesday, March 6, 2013 at 3:09pm

physics
A vehicle with a mass of 2 tons travels on a horizontal road at a speed of 126km/h.The driver notices a donkey at the side of the road and decides to reduce speed. The brakes are applied and the vehicle slows down to 72km/h after 5 seconds. Calculate the distance travelled ...
Wednesday, March 6, 2013 at 1:17pm

Physics
An elevator is moving down with an acceleration of 1.40m/s^2.A 14.5-kg block hangs from a spring balance fixed to the roof of the elevator.What is the apparent weight of the block?
Wednesday, March 6, 2013 at 12:50pm

physics
A vehicle with a mass of 2 tons travels on a horizontal road at a speed of 126km/h.The driver notices a donkey at the side of the road and decides to reduce speed. The brakes are applied and the vehicle slows down to 72km/h after 5 seconds. Calculate the acceleration of the ...
Wednesday, March 6, 2013 at 12:15pm

physics
A capacitor consists of two concentric spherical shells. The outer radius of the inner shell is a=0.76 mm and the inner radius of the outer shell is b=3.31 mm . (a) What is the capacitance C of this capacitor? Express your answer in Farads. unanswered (b) Suppose the Maximum ...
Wednesday, March 6, 2013 at 11:21am

Physics
We use a wrench to turn nuts on bolts because they require less force. Consider a hexagonal nut 1 cm in diameter. We can tighten this nut with one of two wrenches, wrench A with lever arm 10 cm and wrench B with lever arm 20 cm. Both wrenches have a very small mass, so you may...
Wednesday, March 6, 2013 at 11:10am

physics
Why are the shaving mirror concave while the rear view mirror convex? Draw the ray diagrams to support your answer.
Wednesday, March 6, 2013 at 10:04am

physics
if the weight of the block,W,is 2.5 kilogram,the coefficient of static friction,0.25,and the coefficient of kinetic friction,0.15,determine: (a) the force necessary to hold the block sliding down (b) the force necessary to pull the block up the plane with uniform speed
Wednesday, March 6, 2013 at 9:21am

physics
How many revolutions per minute would a 15 -diameter Ferris wheel need to make for the passengers to feel "weightless" at the topmost point?
Wednesday, March 6, 2013 at 8:44am

Physics
A 79.4-Ω and a 47.7-Ω resistor are connected in parallel. When this combination is connected across a battery, the current delivered by the battery is 0.296 A. When the 47.7-Ω resistor is disconnected, the current from the battery drops to 0.126 A. (a) Determine...
Wednesday, March 6, 2013 at 5:06am

physics
The units of heat are equivalent to those of which one of the following quantities?
Wednesday, March 6, 2013 at 4:38am

physics
The coefficient of volume expansion for iron is 3.6 x 10-5/Co. If a 17 m long rod of iron is cooled from 100oC to 5oC, what it the new length?
Wednesday, March 6, 2013 at 4:34am

physics
Suppose H⊗3|ϕ⟩=12√(|000⟩+|111⟩). What is |ϕ⟩? Specify the probability amplitude for each component:
Wednesday, March 6, 2013 at 4:05am

physics
Given circuits for f and f−1, we can create classical reversible circuits Rf, R−1f, Rf−1, R−1f−1 which are shown in the following figure. (Assume that f is a bijection.)In what sequence shall we apply the above circuits in order to implement a ...
Wednesday, March 6, 2013 at 4:02am

Physics
A 100 watt bulb emits light in all directions. The distance R from the bulb is equal to 1.0 meter. Complete the table below with calculated values of intensity of the bulb. Distance from Source Intensity (W/m2) R ? 2R ? 3R ? c) If the bulb was replaced by a 75 watt bulb, at ...
Tuesday, March 5, 2013 at 10:25pm

Physics
A radio tunes in radio waves which have a wavelength of 3.13 meters. What frequency is the radio tuned to in MHz?
Tuesday, March 5, 2013 at 10:20pm

Physics
An astronomer looks at a comet which is 5.92 x 109 km away. How many minutes did it take the light from the comet to reach the astronomer?
Tuesday, March 5, 2013 at 10:18pm

physics
The electrons in a beam are moving at 2.8 × 108 m/s in an electric ﬁeld of 17000 N/C. What value must the magnetic ﬁeld have if the electrons pass through the crossed ﬁelds undeﬂected? Answer in units of µT
Tuesday, March 5, 2013 at 9:54pm

physics
A 346 W bulb and a 173 W bulb are both designed to operate at standard household voltage of 120 V. Determine which bulb has the lower ﬁlament resistance and then calculate the value of its resistance. Answer in units of Ω
Tuesday, March 5, 2013 at 9:53pm

Physics
At t = 0, a wheel rotating about a fixed axis at a constant angular deceleration of 0.37 rad/s2 has an angular velocity of 0.5 rad/s and an angular position of 8.5 rad. What is the angular position of the wheel after 2 s? Answer in units of rad
Tuesday, March 5, 2013 at 8:22pm

Physics
An airplane is flying in a horizontal circle at a speed of 104 m/s. The 73.0 kg pilot does not want the centripetal acceleration to exceed 6.98 times free-fall acceleration. Find the minimum radius of the plane’s path. The acceleration due to gravity is 9.81 m/s2. Answer ...
Tuesday, March 5, 2013 at 8:02pm

physics
Tarzan, King of the Jungle (mass = 73.2 kg), grabs a vine of length 14.1 m hanging from a tree branch. The angle of the vine was 25.9° with respect to the vertical when he grabbed it. At the lowest point of his trajectory, he picks up Jane (mass = 41.0 kg) and continues ...
Tuesday, March 5, 2013 at 7:52pm

physics
Jacob found a piece of a broken glass bottle. He picked it up and made these observations about it: 1. No color (clear) 2. Makes scratches on wood 3. Has a bumpy surface 4. Broke when I dropped it He thinks the glass is a solid and most of his observations could only apply to ...
Tuesday, March 5, 2013 at 7:43pm

Physics..PLZ HELP!
The magnitude of the magnetic field 8.0 cm from a straight wire carrying a current of 6.0 A is A) 3.0 ƒÎ ~ T. B) 1.5 ~ T. C) 1.5 ~ T. D) 3.0 ~ T. E) 3.0 ~ T.
Tuesday, March 5, 2013 at 7:39pm

Physics
A wire of thickness d = 5 mm is tightly wound 200 times around a cylindrical core to form a solenoid. A current I = 0.1 A is sent through the wire. What is the magnetic field on the axis of the solenoid?
Tuesday, March 5, 2013 at 7:25pm

physics
How fast would a 4-g fly have to be traveling to slow a 1890-kg car traveling at 51 mph by 6 mph if the fly hit the car in a totally inelastic head-on collision?
Tuesday, March 5, 2013 at 7:21pm

physics
The speed of all electromagnetic waves in empty space is 3.00 × 108 m/s. What is the wavelength of visible light emitted at 7.2 × 108 MHz? Answer in units of m
Tuesday, March 5, 2013 at 7:02pm

Physics ~Thermodynamics~
* Pressure * 1) what other ways can the pressure of a gas be changed? * Internal Energy * 2) A cup of hot tea is poured from a teapot, and a swimming pool if filled with cold water. a) Which one has a higher internal energy? b) Which has a higher average of kinetic energy? * ...
Tuesday, March 5, 2013 at 6:15pm

Physics
A 1200.0-kg car speeds up from 16.0 m/s to 20.0 m/s. How much work was done on the car to increase its speed?
Tuesday, March 5, 2013 at 5:24pm

physics
From the top of a tall building, a gun is fired. The bullet leaves the gun at a speed of 340 m/s, parallel to the ground. As the drawing shows, the bullet puts a hole in a window of another building and hits the wall that faces the window. (y = 0.56 m, and x = 7.0 m.) Using ...
Tuesday, March 5, 2013 at 4:12pm

Physics
A basketball is thrown from the ground into the air at an angle of 30 degrees to the horizontal. If this object reaches a maximum height of 5.75m, at what velocity was it thrown? How am i suppose to do this question if no velocity is given? I need help. I have a test tomm.
Tuesday, March 5, 2013 at 4:06pm

Physics
A sled rope is held at an angle of 45 degrees with the horizontal ground. A force of 60 N acting parallel to the ground is required to keep the sled in motion. How much force must be exerted on the rope?
Tuesday, March 5, 2013 at 3:11pm

Physics
A boat is pulled through a canal by horses walking parallel to the canal and exerting a force of 1000 N on a tow rope 40 meters long. If the distance from the boat to the horse track is 15 meters, what is the magnitude of the effective component pulling the boat forward?
Tuesday, March 5, 2013 at 3:09pm

Physics
An 67.6 kg object moving to the right at 38.7 cm/s overtakes and collides elastically with a second 48.9 kg object moving in the same direction at 19.2 cm/s. Find the velocity of the second object after the collision. Answer in units of cm/s
Tuesday, March 5, 2013 at 3:03pm

Physics
High-speed stroboscopic photographs show that the head of a 197 g golf club is traveling at 36.8 m/s just before it strikes a 45.9 g golf ball at rest on a tee. After the collision, the club head travels (in the same direction) at 25.9 m/s. Find the speed of the golf ball ...
Tuesday, March 5, 2013 at 2:00pm

Physics
A dart gun is located 1 meter above the floor and is fired horizontally. the dart travels a horizontal distance of 4 meters when it hits the floor. what is the initial velocity if the dart when fired?
Tuesday, March 5, 2013 at 12:59pm

physics
the resistance of copper wire of length 1m is 0.1 ohm the diameter of the wire is 0.045cm find its specific resistance
Tuesday, March 5, 2013 at 12:02pm

Physics
I came here earlier with this question: "A force of 20 N acts toward the west. Another force acts at the same point so that the resultant of the two forces is zero. What is the magnitude and direction of the second force?" I was wondering if someone could explain to ...
Tuesday, March 5, 2013 at 10:59am

Physics
An object with mass 8.2 kg is attached to a spring with spring stiffness constant 370 N/m and is executing simple harmonic motion. When the object is 0.16 m from its equilibrium position, it is moving with a speed of 0.31 m/s. Calculate the maximum velocity attained by the ...
Tuesday, March 5, 2013 at 10:21am

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