Homework Help: Science: Physics

Recent Homework Questions About Physics

Physics
A ladder (L = 7.80 m) of weight WL = 360 N leans against a smooth vertical wall. The term "smooth" means that the wall can exert only a normal force directed perpendicular to the wall and cannot exert a frictional force parallel to it. A firefighter, whose weight is ...
Monday, March 4, 2013 at 7:12pm

Physics
In a target shooting game, wooden blocks are thrown into the air and shot in flight. A block of 0.8kg has a speed of 10 m/s at the top of its trajectory when it is hit by a bullet from below at an angel 60° from horizontal. The mass of the bullet is 5.0 g and its speed is ...
Monday, March 4, 2013 at 7:06pm

Physics
Two curves on a highway have the same radii. However, one is unbanked and the other is banked at an angle θ. A car can safely travel along the unbanked curve at a maximum speed v0 under conditions when the coefficient of static friction between the tires and the road is...
Monday, March 4, 2013 at 7:05pm

physics
In the figure, a frictionless roller coaster car of mass m = 672 kg tops the first hill with speed v0 = 19.4 m/s at height h = 34.7 m. How much work does the gravitational force do on the car from that point to (a) point A, (b) point B, and (c) point C? If the gravitational ...
Monday, March 4, 2013 at 6:47pm

physics
An ocean wave travels 17.1 m in 6.7 s. The distance between the two nearest wave crests is 5.1 m. What is the frequency of the wave? Answer in units of H
Monday, March 4, 2013 at 6:33pm

Physics
A battery with an emf of 7.9 V and internal resistance of 1.37 Ω is connected across a load resistor R.If the current in the circuit is 0.88 A, what is the value of R? Answer in units of Ω What power is dissipated in the internal resistance of the battery? Answer ...
Monday, March 4, 2013 at 5:11pm

Physics
If the emf of a battery is 23 V and a current of 66 A is measured when the battery is shorted, what is the internal resistance of the battery? Answer in units of Ω How would you set up the equation to solve?
Monday, March 4, 2013 at 5:09pm

Physics
A horizontal spring is lying on a frictionless surface. One end of the spring is attaches to a wall while the other end is connected to a movable object. The spring and object are compressed by 0.076 m, released from rest, and subsequently oscillate back and forth with an ...
Monday, March 4, 2013 at 4:31pm

physics
An electron is projected, with an initial speed of vi=1.38e+05 m/sec, directly towards a proton that is essentially at rest. If the electron is initially a great distance from the proton, at what distance from the proton is its speed instantaneously equal to twice its initial ...
Monday, March 4, 2013 at 2:58pm

statistics
Percentage grades in a large physics class follow a normal distribution with mean 58. It is known that 3% of students receive grades less than 39.2. What is the standard deviation of grades in the class?
Monday, March 4, 2013 at 1:39pm

Physics III
The “average” driver drives ~15,000 miles per year. Let’s assume ~10,000 miles of that is interstate driving. Using your models from parts (b) and (c) again, how much does the average driver spend per year if their average speed is 55 mph, 65 mph, and 75 mph? ...
Monday, March 4, 2013 at 1:32pm

Physics II
It is ~ 100 miles of mostly interstate driving to camp. Using your model from parts (b) and (c), how much does it cost me to drive to camp if I drive 55 mph, 65 mph, and 75 mph? (don’t forget the return trip) the current price of gas for part c is 3.89/gal I have tried to...
Monday, March 4, 2013 at 1:29pm

Physics
Develop a model for the effective gas mileage (call it E) as a function of speed (S) for a ¡°typical¡± car (you should be able to find the necessary information to develop this model for your own car). This model should be valid for 55 ¡Ü S &...
Monday, March 4, 2013 at 1:26pm

Physics
A 200-pound boy lifts a 40-kilogram box off of the floor 1.3 meters in 0.7 seconds. His brother lifts a 48-kilogram box off the floor 0.9 meters in 0.6 seconds. Which boy is more powerful? Explain.
Monday, March 4, 2013 at 12:33pm

Physics
Relative to some reference points , ur nose is in motion when you run. Relative to othrrs, its not in motion. Give one example of each,
Monday, March 4, 2013 at 12:27pm

Physics
If you walk 2 km from your house to a store then back home, whats your displacement? (Displacement is the difference between 1st position and final position)
Monday, March 4, 2013 at 12:20pm

Physics please help!!
Assume a circular orbit. If a planet's distance from it star is multiplied by 25 times, then by how many times is its orbital period T multiplied ?
Monday, March 4, 2013 at 10:46am

Physics please help!!
A satellite is in a circular orbit very close to the surface of a spherical planet. The period of the orbit is 2.23 hours. What is density of the planet? Assume that the planet has a uniform density.
Monday, March 4, 2013 at 10:38am

physics
Suppose we have |ϕ⟩=∑y∈{0,1}n 46;y|y⟩ such that βy=0 if s⋅y=1mod2 and βy=12(n−1)/2 if s⋅y=0mod2, where s is some hidden n-bit string. (a) If we run Fourier sampling on |ϕ⟩, what is the probability ...
Monday, March 4, 2013 at 3:26am

physics
what is the minimum riding speed needed to be able to hear the whistle? Remember, you can assume the following things: The whistle you use to call your hunting dog has a frequency of 21.0 kHz, but your dog is ignoring it. You suspect the whistle may not be working, but you can...
Monday, March 4, 2013 at 1:28am

physics
two point charges q1=3uc and q2=-2uc are placed 5 cm apart on the x asix. at what points along the x asix in a) the electric field zero and b) the potential zero ?
Sunday, March 3, 2013 at 10:19pm

Physics
A 41.2-kg boy, riding a 2.57-kg skateboard at a velocity of +5.82 m/s across a level sidewalk, jumps forward to leap over a wall. Just after leaving contact with the board, the boy's velocity relative to the sidewalk is 6.12 m/s, 9.72° above the horizontal. Ignore any ...
Sunday, March 3, 2013 at 10:09pm

Physics
A 6 uF capacitor is initially charged to 100V and then connected across a 600 ohm resistor. a) what is the initial charge on the capacitor?
Sunday, March 3, 2013 at 9:53pm

physics
An electric field of 850 kV/m is desired between two parallel plates, each area 7cm x 5 cm and separated by 2.5 mm of air. a) what charge must be on each plate ? b) how much energy is stored ?
Sunday, March 3, 2013 at 9:09pm

Physics
Let U=(13i3−i). What is U†? Explicitly indicate multiplication with a * symbol. For instance, you should write 3*i+2 instead of 3i+2.
Sunday, March 3, 2013 at 8:53pm

Physics help!
Two equal point charges of 5 µC are on the horizontal axis. One charge is at -10 cm, the other is at +10 cm.? These two charges don't move, they are STUCK, take the potential to be zero at infinity. Find the potential at the following coordinates: (0,0) cm, (0,10)cm...
Sunday, March 3, 2013 at 7:29pm

Physics
Find the electric field between the plates of a capacitor given the following: (1) C= 10pF (2) the capacitor is connected to a 25 V battery (3) there is a vacuum between the capacitor plates (4) plate separation is 2 mm
Sunday, March 3, 2013 at 6:58pm

Hard physics
Two equal point charges of 5 µC are on the horizontal axis. One charge is at -10 cm, the other is at +10 cm.? These two charges don't move, they are STUCK, take the potential to be zero at infinity. Find the potential at the following coordinates: (0,0) cm, (0,10)cm...
Sunday, March 3, 2013 at 6:57pm

College physics
Open Question: Find the electric field between the plates of a capacitor given the following:? (1) C= 10pF (2) the capacitor is connected to a 25 V battery (3) there is a vacuum between the capacitor plates (4) plate separation is 2 mm
Sunday, March 3, 2013 at 6:40pm

College physics
Open Question: Two equal point charges of 5 µC are on the horizontal axis. One charge is at -10 cm, the other is at +10 cm.? These two charges don't move, they are STUCK, take the potential to be zero at infinity. Find the potential at the following coordinates: (0,0...
Sunday, March 3, 2013 at 6:39pm

physics
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y direction so the proton will just reach the point (0,20) cm?
Sunday, March 3, 2013 at 6:28pm

Physics science 1206
You are coasting on your skateboard at 1.4 m/s and you decide to speed up. if you accelerate at 05 m/s2 (square) for 7.0s what is your final speed?
Sunday, March 3, 2013 at 6:18pm

Quantum Physics
Suppose Alice starts with two qubits in the Bell state 1/√2 (|00> + |11>) and teleports these qubits to Bob by applying the quantum teleportation protocol to each qubit separately. (a) What is the state of the two qubits received by Bob? |00> = |01> = |10>...
Sunday, March 3, 2013 at 6:11pm

Quantum Physics
Suppose H|ψ> = 1/√2 (|000> + |111>). What is |ψ> ? Specify the probability amplitude for each component: |000> = |001> = |010> = |011> = |100> = |101> = |110> = |111> =
Sunday, March 3, 2013 at 6:07pm

College Physics
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y direction so the proton will just reach the point (0,20) cm?
Sunday, March 3, 2013 at 6:01pm

Physics
A 20 kg crate is placed on a horizontal conveyor belt. The materials are such that us = 0.47 and uk = 0.21. What is the maximum acceleration the belt can have without the crate slipping? If acceleration of the belt exceeds the value determined in part A, what is the ...
Sunday, March 3, 2013 at 5:46pm

Physics
500 calories of heat is added to 2.0 g of water at 80 degrees Celsius. How much steam is produced?
Sunday, March 3, 2013 at 5:18pm

Physics
A specimen has .625 the amount of carbon 14 you would find in a living specimen. How many half-lives has the specimen been through? How old is the specimen?
Sunday, March 3, 2013 at 5:13pm

physics
If a hollow metal cylinder of radius r is rolling towards a circular bump of height h. calculate the minimum speed needed to progress over a circular bump.
Sunday, March 3, 2013 at 4:56pm

Physics
A 23 kg child goes down a straight slide inclined 38 degrees above horizontal. The child is acted on by his weight, the normal force from the slide, and kinetic friction.
Sunday, March 3, 2013 at 4:24pm

Physics
A horizontal spring is lying on a frictionless surface. One end of the spring is attaches to a wall while the other end is connected to a movable object. The spring and object are compressed by 0.074 m, released from rest, and subsequently oscillate back and forth with an ...
Sunday, March 3, 2013 at 4:13pm

Physics
In unit-vector notation, what is the torque about the origin on a particle located at coordinates (0, -2.24 m, 9.78 m) due to (a) force 1 with components F1x = 2.70 N and F1y = F1z = 0, and (b) force 2 with components F2x = 0, F2y = 2.92 N, F2z = 4.02 N?
Sunday, March 3, 2013 at 3:38pm

maths and physics
A particle of mass 4 kg is attached to one end of an inelastic string and a particle of mass 2 kg is attached to the other end of the string.The string has length 4m and is hung over a smooth pivot at its midpoint. The Pivot lies 3m above the ground.How long does it take for ...
Sunday, March 3, 2013 at 3:37pm

maths and physics
A cannon is placed on a hillside pointing up the hill, where the hill is at an angle a Pi/4 to the horizontal. The cannon points at an angle Pi/6 to the slope. and a shot is red uphill with initial speed v0. (i) Find the maximum value of the distance between the ...
Sunday, March 3, 2013 at 3:36pm

Physics
A rocket in a fireworks display explodes high in the air. The sound spreads out uniformly in all directions. The intensity of the sound is 3.14 x 10-6 W/m2 at a distance of 121 m from the explosion. Find the distance (in m) from the source at which the intensity is 1.80 x 10-6...
Sunday, March 3, 2013 at 3:11pm

Physics
In a room that is 2.69 m high, a spring (unstrained length = 0.28 m) hangs from the ceiling. A board whose length is 2.22 m is attached to the free end of the spring. The board hangs straight down, so that its 2.22-m length is perpendicular to the floor. The weight of the ...
Sunday, March 3, 2013 at 2:50pm

Physics
A woman is standing in the ocean, and she notices that after a wave crest passes by, five more crests pass in a time of 68.0 s. The distance between two successive crests is 34.1 m. What is the wave's (a) period, (b) frequency, (c) wavelength, and (d) speed?
Sunday, March 3, 2013 at 2:44pm

Physics
The mass of a string is 6.8 x 10-3 kg, and it is stretched so that the tension in it is 210 N. A transverse wave traveling on this string has a frequency of 190 Hz and a wavelength of 0.67 m. What is the length of the string?
Sunday, March 3, 2013 at 2:26pm

Physics
A string has a linear density of 6.2 x 10-3 kg/m and is under a tension of 250 N. The string is 1.2 m long, is fixed at both ends, and is vibrating in the standing wave pattern shown in the drawing. Determine the (a) speed, (b) wavelength, and (c) frequency of the traveling ...
Sunday, March 3, 2013 at 2:24pm

Physics
The distance between a loudspeaker and the left ear of a listener is 2.19 m. (a) Calculate the time required for sound to travel this distance taking the speed of sound to be 343 m/s. (b) Assuming that the sound frequency is 525 Hz, how many wavelengths of sound are contained ...
Sunday, March 3, 2013 at 2:23pm

Physics
A bird is flying directly toward a stationary bird-watcher and emits a frequency of 1390 Hz. The bird-watcher, however, hears a frequency of 1430 Hz. What is the speed of the bird, expressed as a percentage of the speed of sound?
Sunday, March 3, 2013 at 2:22pm

physics
suppose you are driving on a straight two lane road at a constant speed of 88 km/h truck travelling at a constant speed of 104 km/h approaches you.what is the truck's velocity relative to you.
Sunday, March 3, 2013 at 2:10pm

Physics
Two out-of-tune flutes play the same note. One produces a tone that has a frequency of 242 Hz, while the other produces 288 Hz. When a tuning fork is sounded together with the 242-Hz tone, a beat frequency of 26.0 Hz is produced. When the same tuning fork is sounded together ...
Sunday, March 3, 2013 at 1:55pm

Physics
If a string fixed at both ends is vibrating at a frequency of 4.61 Hz and the distance between two successive nodes is 0.293 m, what is the speed of the waves on the string?
Sunday, March 3, 2013 at 1:38pm

Physics
A string is fixed at both ends and vibrating at 120 Hz, which is its third harmonic frequency. The linear density of the string is 4.9x10-3 kg/m, and it is under a tension of 3.6 N. Determine the length of the string.
Sunday, March 3, 2013 at 1:37pm

PHYSICS
There is a mass at the end of a 0.6 m string, being swung around overhead at constant acceleration of(3/4)pi rad/sec^2. mass is 39.84 G. Tensile strength is 12.4 newtons need to find how many revolutions there will be before the string breaks, and the time before that happens...
Sunday, March 3, 2013 at 1:27pm

physics
A truck of mass 13,100 kg is acted upon by a driving force of 8900 N. The motion is opposed by a frictional force of 2230 N. Find the acceleration.
Sunday, March 3, 2013 at 1:01pm

physics
A carnival ride has a radius of 2.18 m and rotates once every 0.82 sec. What would the speed of a rider be that has been flung from the ride? What would be the angular speed of a second rider who remains on the ride?
Sunday, March 3, 2013 at 12:51pm

physics
Eelectrons, like all forms of matter, fall under the influence of gravity. if a electron is projected horizontly with a speed of one-tenth speed of light, how far will it fall in traversing 1 meter of horizontal distance.
Sunday, March 3, 2013 at 10:39am

Physics
Assume that in interstellar space the distance between two electrons is about 0.87 cm. The electric force between them are repulsive. Calculate the electric force between these two electrons. The value of the Coulomb constant 9 × 109 N · m2/C2 and the elemental ...
Sunday, March 3, 2013 at 10:01am

Physics
At what temp would an intrensic semiconductor behave like a perfect insulator?Why?
Sunday, March 3, 2013 at 1:43am

physics
Two conducting thin hollow cylinders are co-aligned. The inner cylinder has a radius R1 , the outer has a radius R2 . Calculate the electric potential difference V(R2)−V(R1) between the two cylinders. The inner cylinder has a surface charge density of σa=−&#...
Sunday, March 3, 2013 at 1:06am

Physics
A 3.0 kg block slides down a 4.5 m ramp of angle 30 degrees and collides inelastically with a 4.5 kg bolck at rest. Calculate the velocity after the collision.
Sunday, March 3, 2013 at 12:57am

physics
A race car travels northward on a straight, level track at a constant speed travels 0.745 km in 22.0 s. The return trip over the same track is made in 27.0 s. (a) What is the average velocity of the car in m/s for the first leg of the run? m/s (b) What is the average velocity ...
Sunday, March 3, 2013 at 12:18am

physics
How would the force of gravity between two masses be affected if the separation distance between them were the following? (Assume F2 represents the new force and F1 represents the original force.) (a) triple the original distance F2 / F1 = (b) one-fourth the original distance ...
Sunday, March 3, 2013 at 12:16am

physics
If a 0.50-kg block initially at rest on a frictionless, horizontal surface is acted upon by a force of 5.7 N for a distance of 8.6 m, then what would be the block's velocity?
Sunday, March 3, 2013 at 12:14am

Physics
Roughly how high could a 340 K copper ball lift itself if it could transform all of its thermal energy into work? Assume specific heat for copper equal to 386 J/kg·K.
Sunday, March 3, 2013 at 12:14am

physics
A projectile is launched at a 60 degree angle above the horizontal with an initial velocity of 35.5 m/s. What is the projectile's velocity (magnitude and direction) 1.50 s into the flight?
Saturday, March 2, 2013 at 10:51pm

Physics
An electron is projected, with an initial speed of v= 2.18e+05 m/sec, directly towards a proton that is essentially at rest. If the electron is initially a great distance from the proton, at what distance from the proton is its speed instantaneously equal to twice its initial ...
Saturday, March 2, 2013 at 9:33pm

Physics
Four students measure the mass of an object, each using a different scale. They record their results as follows: Student A B C D Mass (g)49.06 49 50 49.1 E 49.061 Which student used the most precise scale?
Saturday, March 2, 2013 at 8:46pm

Physics
Could someone please explain how you get this answer??? A skier with a mass of 60.0 kg pushes off with a horizontal speed of 3.0 m/s from the top of a snow covered hill. As he slides down the hill, his height decreases by 42 m over a distance of 100 m of travel. How much will ...
Saturday, March 2, 2013 at 6:10pm

Physics
An air-track cart of mass 0.10 is moving with a speed 1.2 to the right when it collides with a cart of mass 0.24 that is at rest. Each cart has a wad of putty on its bumper, and hence they stick together as a result of their collision. Suppose the average contact force between...
Saturday, March 2, 2013 at 2:48pm

Physics
A 80.0 Hz generator with an rms voltage of 150 V is connected in series to a 3.20 k ohm resistor and a 3.50 micro farad capacitor. Find the phase angle between the current and the voltage.
Saturday, March 2, 2013 at 2:42pm

Physics
A mass of 100 gram is fallen down,which will be the kinetic energy after 5 second of its fall?
Saturday, March 2, 2013 at 2:15pm

Physics
A child with a mass of 35.0 kg climbs onto a water slide that is 2.00 m above the water as shown. The child does not push off, and so is at rest when the sliding begins. The slide is very slippery, and is considered frictionless. (i) What is the work done by the normal force ...
Saturday, March 2, 2013 at 1:38pm

Physics
The average power output of a human heart is 1.3 3 Watts. You had to pay for this energy at Wis consin Energy’s rate of $0.12061 per kWh (kiloWatt hour), what is the cost?
Saturday, March 2, 2013 at 1:35pm

Physics
Alpengeist, in Williamsburg, Virginia, promises the world’s largest inverted (upside-down) loop, with a diameter of 106 feet (32.3 m). (i) What is the minimum safe speed while inverted? (ii) If the actual speed is 52.0 mph while inverted(23.25 m/s), then what is the ...
Saturday, March 2, 2013 at 12:57pm

physics
a mass of 0.2kg is attached to a spring of negligible mass. if the mass executes simple harmonic motion with a period of 0.5s, what will be the spring constant?
Saturday, March 2, 2013 at 11:44am

Physics
X and Y are two capacitors(parallel plate) connected in series to a 12V supply.X has air between the plates and its capacitance is 10microfarads.Y contains a dielectric medium of K=5.calculate capacitance of Y and the potential difference between the plates of Y.
Saturday, March 2, 2013 at 5:37am

Physics
in a wire AB of uniform cross section in which a potential gradient of 0.1 V/m exist.If the balancing point is foung to be 180 cm from A then what is the Emf of the cell?
Saturday, March 2, 2013 at 5:28am

Physics
what is the power dissipated in an ac circit in which current v=230sin(wt+90) and I=10sin(wt)...plz help me
Saturday, March 2, 2013 at 5:24am

Physics
what is the volume of water displaced for 1.1 of pure gold.
Saturday, March 2, 2013 at 4:34am

PHYSICS
A force 1 Mega-dyne is forced agaist a running body to stop it.If the kinetic energy of the body is 1 Joule,then how much distance it will go before stopping?
Saturday, March 2, 2013 at 12:13am

Physics
train car with mass m1 = 521 kg is moving to the right with a speed of v1 = 7.9 m/s and collides with a second train car. The two cars latch together during the collision and then move off to the right at vf = 5.1 m/s. 1)What is the initial momentum of the first train car? I ...
Friday, March 1, 2013 at 11:44pm

physics
A package slides down a 135 m long ramp with no friction. If the package starts from rest at the top and is to have a speed no faster than 19m/s at the bottom, what should be the maximum angle of inclination?
Friday, March 1, 2013 at 11:23pm

physics
the coefficient of friction between a block of weight 15N and a horizontal board on which it is resting is 3.0find the horizontal force which will just remove the block and the force acting at an angle of 30 with the horizontal which will just move the block.
Friday, March 1, 2013 at 9:37pm

Physics
A space probe is carried by a rocket into outer space where it continues to move on its own in a straight line. What keeps the probe moving? Is the answer: the gravitation forces from diﬀerent stars and planets
Friday, March 1, 2013 at 8:08pm

Physics
If a Mack truck and Honda Civic have a headon collision, upon which vehicle is the impact force greater and which vehicle experiences the greater acceleration? I know they have same force.
Friday, March 1, 2013 at 8:01pm

Physics
1)The Earth exerts an 710 N gravitational force on a man. What force does the man exert on the Earth? Answer in units of N 2)If a book is sitting on a table, the force of gravity pulls it down. Why doesn’t it fall? Is it because The table is pushing up on it with a force ...
Friday, March 1, 2013 at 7:49pm

Physics
You hit someone with a force of 197 N. How much force is exerted on you? Answer in units of N Is the answer 197 N
Friday, March 1, 2013 at 7:44pm

Physics
You hit someone with a force of 197 N. How much force is exerted on you? Answer in units of N
Friday, March 1, 2013 at 7:28pm

Physics
Suppose you are stopped for a traffic light, and an ambulance approaches you from behind with a speed of 19.0 m/s. The siren on the ambulance produces sound with a frequency of 960 Hz as measured when you are at rest relative to the ambulance. The speed of sound in air is 343 ...
Friday, March 1, 2013 at 7:06pm

Physics
Recently, Asteroid 2012 DA14 came within 34,200 km from the center of the earth at its point of closest approach. If the moon goes around the earth once every 27.5 days, what is the ratio of the distance of closest approach of DA14 to the radius of the orbit of the moon?
Friday, March 1, 2013 at 6:43pm

physics
Scientists plan to release a space probe that will enter the atmosphere of a gaseous planet. The temperature of the gaseous planet varies linearly with the height of the atmosphere. The delicate instruments on board completely fail at a height of 61.5 kilometers. What is the ...
Friday, March 1, 2013 at 4:17pm

physics
Suppose that the pressure of an ideal gas mixture remains constant at 1700 Pa (1 Pa = 1 N/m2) and the temperature is increased from 400K to 800K. How much work does the gas do to the surroundings during expansion?
Friday, March 1, 2013 at 3:54pm

physics
if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
Friday, March 1, 2013 at 2:19pm

Physics
In a "Rotor-ride" at a carnival, people are rotated in a cylindrically walled "room." The radius of the room is 4.0 m, The coefficient of static friction is μ=0.13. What is the minimum rotation frequency such that the people will not slide down the ...
Friday, March 1, 2013 at 2:07pm

Physics
Superman, who likes physics, dangles his watch from a thin piece of string while he is taking off from ground horizontally at a constant acceleration a. He notices that the string makes an angle of θ with respect to the vertical. After 18 seconds, his speed is v=116m/s. ...
Friday, March 1, 2013 at 2:06pm

Physics
A 0.4kg ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.3 m on a frictionless horizontal surface. If the cord will break when the tension in it exceeds 65 N, what is the maximum rpm(revolution per minute) the ball can have? HELP?
Friday, March 1, 2013 at 1:53pm

Physics
What current is produced by a ring with a radius of 0.5 m and a uniform positive linear charge density of 1 microCoulomb/m rotatingwith an angular frequency of 4π/s? a. 1 microAmpere b. 3.14 microAmpere c. 6.28 microAmpere d. 12.6 microAmpere
Friday, March 1, 2013 at 12:23pm

Physics
Suppose that you wish to fabricate a uniform wire out of 1 g of copper. (Resistivity = 1.72*10^-8 Ohm-m, density = 8.94*10^3kg/m^3). If the wire is to have a resistance of R = 0.5 ohm and all of the copper is to be used, how long is the wire? a. 1765 m b. 1816 m c. 1.8 m d. 0....
Friday, March 1, 2013 at 12:22pm

Physics
A current of 4.00 A flows through the heating element of heater converting 500 J of electrical energy into thermal energy every second. What is the voltage across the ends of the heating element? a. 2000 V b. 125 V c. 250 V d. 0.008 V e. 0.125 V
Friday, March 1, 2013 at 12:20pm

physics
at what inclination should the object be released from rest if it is to reach a maximum horizontal distance of 2m as shown. coeff of friction is 0.37 for all surfaces of contact.
Friday, March 1, 2013 at 11:18am

physics
Find è and W in the figure below where w1 = 17.0 N, w2 = 31.0 N, and á = 67.5°, assuming that the arrangement is at rest.
Friday, March 1, 2013 at 10:17am

physics
An idealized voltmeter is connected across the terminals of a 15.0- battery, and a 72.5- appliance is also connected across its terminals. If the voltmeter reads 11.0 .
Friday, March 1, 2013 at 9:01am

physics
blue-green light has a frequency of about 6X10 to the fourth Hz. use the relationship c=fl to find the wavelength of this light in air. how does this wavelength compare with the size of the atom, which is about 10 is to ten?
Friday, March 1, 2013 at 7:11am

physics
What is the orbital radius and speed of a synchronous satellite which orbits the earth once every 24h?
Friday, March 1, 2013 at 4:42am

physics
Suppose we have two qubits in the state (a|0⟩+b|1⟩)|0⟩, to which we apply the following circuit. (a) Is the resulting state entangled? Yes No (b) Specify the state of each qubit after we applied the circuit.
Friday, March 1, 2013 at 4:07am

physics
Help me solve this physics homework: in sense we all have kinetic energy,even when we are standing still.the earth with a radius of 6.37*10power6 m,rotates about its axis once a day.ignoring the earths rotation about the sun,what is the K.E of a 50Kg man standing on the ...
Friday, March 1, 2013 at 2:14am

Physics
A projected space station consists of a circular tube that is set rotating about its center (like a tubular bicycle tire) as shown in figure below. The circle formed by the tube has a diameter of about D = 1.28km. What must be the rotation speed (in revolutions per day) if an ...
Friday, March 1, 2013 at 12:12am

physics
The light from the sun is found to have a maximum intensity near the wave length of 470nm assuming the surface of the sun as a black body,the temperature of the sun is....
Thursday, February 28, 2013 at 10:50pm

Physics
A 1000 kg car is accelerated from rest to 100 miles/hour in 10 seconds. Find the output power of this car
Thursday, February 28, 2013 at 10:37pm

Physics
For launching a satellite into orbit around earth, would the proper conservation of energy formula be: Epi + Eki + O work = Epf + Ekf? Would work = 0 for launching a satellite? And, would Epi = -Gm1m2/radius of earth or would it just equal 0 (because we usually set Ep on earth...
Thursday, February 28, 2013 at 10:17pm

physics
In moving out of a dormitory at the end of the sememster, a student does 1.8 104 J of work. In the process, his internal energy decreases by 4.2 104 J. Determine each of the following quantities (including the algebraic sign). a) W b) U c) Q
Thursday, February 28, 2013 at 9:08pm

Physics
An automobile is brought to a stop by applying friction brakes to the wheels. The brakes get hot; their thermal energy is increased. The decrease in kinetic of the car is equal to the increase in thermal energy of the brakes. According to the first law of thermodynamics, the ...
Thursday, February 28, 2013 at 7:57pm

physics
Two point charges totaling 9.00 µC exert a repulsive force of 0.300 N on one another when separated by 0.596 m. (A) What is the charge on each? (B) What is the charge on each if the force is attractive? smallest charg
Thursday, February 28, 2013 at 7:35pm

Physics!!!!
Assume that a scale is in an elevator on the earth. What force would the scale exert on a 53 kg person standing on it when the elevator slows at 1.77 m/s2 while moving upward?
Thursday, February 28, 2013 at 7:30pm

physics
In a cloud chamber experiment, a proton enters a uniform 0.260 magnetic field directed perpendicular to its motion. You measure the proton's path on a photograph and find that it follows a circular arc of radius 6.38 . How fast was the proton moving?
Thursday, February 28, 2013 at 7:27pm

Physics
A conical pendulum is formed by attaching a 0.200kg ball to a 1.00 m-long string, then allowing the mass to move in a horizontal circle of radius 40.0cm . The figure (Figure 1) shows that the string traces out the surface of a cone, hence the name. A) What is the tension in ...
Thursday, February 28, 2013 at 6:29pm

Physics
Dry air will break down if the electric field exceeds about 3.0 × 106 V/m. What amount of charge can be placed on a capacitor if the area of each plate is 6.7 cm2?
Thursday, February 28, 2013 at 6:21pm

physics
The two plates of a capacitor hold +3200 µC and -3200 µC of charge, respectively, when the potential difference is 700 V. What is the capacitance?
Thursday, February 28, 2013 at 6:19pm

Physics
A 220g block on a 54.0cm -long string swings in a circle on a horizontal, frictionless table at 70.0 rpm. A) What is the speed of the block? m/s B) What is the tension in the string? N
Thursday, February 28, 2013 at 6:02pm

Physics
The ship in Figure P14.35 travels along a straight line parallel to the shore and a distance d = 500 m from it. The ship’s radio receives simultaneous signals of the same frequency from antennas A and B, separated by a distance L = 800 m. The signals interfere ...
Thursday, February 28, 2013 at 4:16pm

physics
Bob is driving 25 m/s and he turns a corner with a radius of 37 m. How much is Bob accelerating?
Thursday, February 28, 2013 at 3:41pm

Physics
A gold wire and a silver wire have the same dimensions. At what temperature will the silver wire have the same resistance that the gold wire has at 20°C?
Thursday, February 28, 2013 at 2:43pm

Physics
A bird stands on a bare power line carrying 2500 amps of current. 600 meters of this wire has a resistance of .009 ohms. If the bird's feet are 3 cm apart, what is the voltage difference between the bird's feet?
Thursday, February 28, 2013 at 2:43pm

Physics
(a) The current through a wire is a steady 2.5 amps. How much current passes through it between t = 0 seconds and t = 4 × 10-4 seconds? (b) The current through a wire is given by I(t) = I0e -at, where I0 = 2.5 amps and a = 6 × 103 s-1. How much electric charge ...
Thursday, February 28, 2013 at 2:42pm

physics
Two curves on a highway have the same radii. However, one is unbanked and the other is banked at an angle θ. A car can safely travel along the unbanked curve at a maximum speed v0 under conditions when the coefficient of static friction between the tires and the road is...
Thursday, February 28, 2013 at 2:27pm

physics
A kite is hovering over the ground at the end of a straight 47-m line. The tension in the line has a magnitude of 14 N. Wind blowing on the kite exerts a force of 17 N, directed 55° above the horizontal. Note that the line attached to the kite is not oriented at an angle ...
Thursday, February 28, 2013 at 2:08pm

physics
the speed of sound in water is 1500m/s how far way from an under see rock show a,b,c diver be show that he can hear is an echo
Thursday, February 28, 2013 at 11:33am

physics
when 1 g of gasoline is burned in an engine about 48 kj of heat is produced. how much mass is lost in the process? do you think this mass change could directly be measured?
Thursday, February 28, 2013 at 11:08am

physics
is the work needed to bring a car's speed from 0 to 10 km/h less than, equal to ,or more than the work needed to bring its speed from 10 to 20 km/h? if the amounts of work are different ,what is the ratio between them?
Thursday, February 28, 2013 at 10:40am

physics
What do you understand by positive and negative zero?
Thursday, February 28, 2013 at 10:34am

physics
A unicorn stands atop a 34° hill. The unicorn gracefully slides down the grassy hill with ì=.16. Calculate the acceleration of the unicorn as it begins to slide down the hill. (b) If the unicorn slides for 13.9s before reaching the bottom, how far did the unicorn ...
Thursday, February 28, 2013 at 10:21am

Physics
There is a mass at the end of a 0.6 m string, being swung around overhead at constant acceleration of(3/4)pi rad/sec^2. mass is 39.84 G. need to find how many revolutions there will be before the string breaks, and the time before that happens.
Thursday, February 28, 2013 at 10:00am

physics
An MP3 player operates with a voltage of 3.7 V, and is using 0.14 W of power. Find the current being supplied by the player's battery.
Thursday, February 28, 2013 at 9:30am

physics
A dray horse is being pulled by a rope across a level plow field by a force of 750.0N exerted at an angle of 47° above the horizontal. If the horse’s velocity is constant and the coefficient of friction is ì=.21, determine the mass of the horse.
Thursday, February 28, 2013 at 9:30am

Pages: <<Prev | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | Next>>

Post a New Question | Current Questions

Homework Help: Science

For Further Reading