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June 20, 2013

Homework Help: Science: Physics

Recent Homework Questions About Physics

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Physics
A 1060 N crate is being pulled across a level floor by a force F of 300 N at an angle of 35° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate in m/s^2
Sunday, January 13, 2013 at 8:55pm

physics
A clerk moves a box of cans down an aisle by pulling on a strap attached to the box. The clerk pulls with a force of 188.0 N at an angle of 26° with the horizontal. The box has a mass of 30 kg, and the coefficient of kinetic friction between the box and the floor is 0.45. ...
Sunday, January 13, 2013 at 8:52pm

physics
A 3.40 kg block is pushed along the ceiling with an constant applied force of F = 82.0 N that acts at an angle θ = 50° with the horizontal. The block accelerates to the right at 5.80 m/s2. Determine the coefficient of kinetic friction between the block and the ceiling...
Sunday, January 13, 2013 at 8:50pm

physics
A box slides down a 26° ramp with an acceleration of 1.19 m/s2. Determine the coefficient of kinetic friction between the box and the ramp. μk =
Sunday, January 13, 2013 at 8:48pm

Physics
Two forces are applied to a car in an effort to accelerate it, as shown below. The first force, F1 = 364 N, is applied at an angle α = 33° to the forward dashed line. The second force, F2 = 522 N, is applied at an angle β = 11° to the forward dashed line. ...
Sunday, January 13, 2013 at 8:47pm

Physics
I just have a question....How to know if the volt is -ve or not? and How to know if a charge has deficit or excess electrons ?
Sunday, January 13, 2013 at 7:49pm

Physics.
A punter kicks a football at an angle of 45 degrees to the ground. The football has an initial velocity of 25 m/s, make a diagram and calculate: a) How long was the football in the air? b) How far does the football travel horizontally? c) What is the maximum height of the ...
Sunday, January 13, 2013 at 7:28pm

physics
as light passes from air to water vi/vr=4/3 find the angle of incidence of a ray of light if the angle or refration is 25 degrees 40 minutes (i is the angle of incidence and r is the angle of refraction)
Sunday, January 13, 2013 at 7:00pm

Physics
In one cycle, an engine burning a mixture of air and methanol (methyl alcohol) absorbs 525 J and expels 413 J. How much work is done by this engine?
Sunday, January 13, 2013 at 6:52pm

Physics
When one gallon of gasoline is burned in a car engine, 1.20 108 J of internal energy is released. Suppose that 0.99 108 J of this energy flows directly into the surroundings (engine block and exhaust system) in the form of heat. If 5.0 105 J of work is required to make the car...
Sunday, January 13, 2013 at 6:51pm

Physics
A 4.2 kg rock is initially at rest at the top of a cliff. Assuming the rock falls into the sea at the foot of the cliff and that its kinetic energy is transferred entirely to the water, how high is the cliff if the temperature of 1.5 kg of water is raised 0.10°C?
Sunday, January 13, 2013 at 6:51pm

physics
A 33.1 g ring that appears to be silver is heated to a temperature of 77°C, and then placed in a calorimeter containing 5.00 10-2 kg of water at 24.0°C. The calorimeter is not perfectly insulated, however, so that 0.14 kJ of energy is transferred by heat to the ...
Sunday, January 13, 2013 at 6:50pm

Physics
When a driver brakes an automobile, friction between the brake disks and the brake pads converts part of the car's translational kinetic energy to internal energy. If a 1500 kg automobile traveling at 42 m/s comes to a halt after its brakes are applied, how much can the ...
Sunday, January 13, 2013 at 6:49pm

physics
A collision occurs between two pucks on an air-hockey table. Puck A has a mass of 0.020 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.040 kg and is initially at rest. The collision is not head-on. After ...
Sunday, January 13, 2013 at 5:43pm

physics
Suppose the charge q2 can be moved left or right along a line connecting charges q1 and q3. Given that q = +15 µC, find the distance from q1 where q2 experiences a net electrostatic force of zero? (The charges q1 and q3 are separated by a fixed distance of 36 cm.) q1=+q...
Sunday, January 13, 2013 at 5:40pm

physics
You kick a .3kg soccer ball at a 30deg. angle. your toe provides an average force of 50N for .5m. How far does the ball go?
Sunday, January 13, 2013 at 5:32pm

physics
In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner?
Sunday, January 13, 2013 at 4:49pm

physics
what is the refrevtion of waves? And what are the laws'of refraction? Also about phase change.
Sunday, January 13, 2013 at 3:36pm

physics
Sound is passing perpendicularly through an open window whose dimensions are 1.1 m  0.75 m. The sound intensity level is 95 dB above the threshold of hearing. How much sound energy comes through the window in one hour?
Sunday, January 13, 2013 at 3:32pm

physics
1. What are the examples of supersonic waves? 2. What is match cone, match no? 3. Define echo? 4. What is the effect of frequency on the velocity of sound in a gas? 5. Mathematical expression of beats. ''based on wave motion''
Sunday, January 13, 2013 at 3:25pm

Physics
A 4.90-kg ball, moving to the right at a velocity of +2.50 m/s on a frictionless table, collides head-on with a stationary 8.00-kg ball. Find the final velocities of the balls if the collision meet the following conditions. (a) elastic 4.9-kg ball = 8-kg ball = (b) completely ...
Sunday, January 13, 2013 at 2:58pm

Physics
How would I determine the height of a mountain if I am given direction cosines of vectors from two points on the base of the mountain to the peak?
Sunday, January 13, 2013 at 1:50pm

physics
Two pieces of metal (A and B) are identical in every way, except that A has a much larger thermal expansion coefficient. If equal amounts of heat are added to both pieces of metal, which metal does more work on its surroundings? 1. A 2. B 3. They do the same work. 4. Unable to...
Sunday, January 13, 2013 at 1:17pm

Physics
A mass of 4.77 kg of chilled water at 0C is placed in a freezer which is kept at −19.2C. Approximately how much electric energy is needed to operate the compressor to cool this water to −19.2 C if the room temperature is maintained at 24.2C? The...
Sunday, January 13, 2013 at 1:16pm

physics
sphere A has a mass of 4.2*10^-2 kg and is tethered to a wall by a thin thread. Sphere a has an excess of 1.2 *10^12 electrons. Sphere B has a deficit of 3.5*10^12 electrons and is o.23 m from sphere A a) determine the angle between the thread and the wall b) determine the ...
Sunday, January 13, 2013 at 1:04pm

physics
The masses of the earth and moon are 5.98 × 1024 and 7.35 × 1022 kg, respectively. Identical amounts of charge are placed on each body, such that the net force (gravitational plus electrical) on each is zero. What is the magnitude of the charge placed on each body?
Sunday, January 13, 2013 at 1:03pm

physics
A weightlifter is bench-pressing 65kg. if at full extension the weight is .7m above his chest, then how much has he done after 10 repetitions (given that he simply lets the weights fall back down) if it takes 15 seconds?
Sunday, January 13, 2013 at 12:45pm

physics
A 200kg turtle running at a speed of .4m/s jumps onto a stationary skateboard that masses 3.6kg. the turtle slows to .2m/s by shooting the skateboard out from under him. how fast is the skateboard moving as a result?
Sunday, January 13, 2013 at 10:37am

Physics
A coil of 50 turns has a cross-sectional area of 4.2x10^-3 m^2. It is placed at an angle to a uniform magnetic field of flux density 2.8 x 10^-2 T, so that the angle = 50degrees. What is the change in flux linkage when the coil is rotated anticlockwise until angle = 0degree?
Sunday, January 13, 2013 at 10:22am

Physics
The crate, m=68kg, is pushed up an incline, θ=24degrees, at a constant velocity with Fp=500N. μk=?
Sunday, January 13, 2013 at 9:51am

Physics
A dog is tugging forward on a leas held by a physics student who is standing still. The dog is tugging with a force of 63N. The student estimates the leash to be at an angle of 25 degrees above the ground. What is the tension in the leash?
Sunday, January 13, 2013 at 9:00am

Physics
What will happen if you try to place two bar magnets of exactly equal size one above the other such that their north poles are on the same side
Sunday, January 13, 2013 at 7:49am

physics
Given three vectors a~=Ài~À4j~+2k~ , b~=3i~+2j~À2k~ , c~=2i~À3j~+k~ , calculate a~Á(b~Âc~)
Sunday, January 13, 2013 at 6:49am

physics
a red blood cell travels at a speed of 40 cm/s in a large artery. a sound with a frequency of 100 kHz enters a blood opposite the direction flow. calculate the frequency of sound reflected from the cell and detected by a receiver. (v = 1500 m/s)
Sunday, January 13, 2013 at 4:05am

physics
a block of ice released from rest at top of 400 m long ramp slides to the bottom in 2.20 seconds. what is the angle between the ramp and the horizontal
Sunday, January 13, 2013 at 3:38am

physics
two forces of 5 N respectively act on an object.when will the resultant of the two vectors be at a maximum?
Sunday, January 13, 2013 at 1:56am

physics PLEASE HELP
Two charges are placed on the x axis. One of the charges (q1 = +7.91C) is at x1 = +3.00 cm and the other (q2 = -27.3C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm.
Saturday, January 12, 2013 at 10:30pm

physics
Two charges are placed on the x axis. One of the charges (q1 = +7.91C) is at x1 = +3.00 cm and the other (q2 = -27.3C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm.
Saturday, January 12, 2013 at 10:30pm

physics
an object's acceleration is given by the function a= 2/v^2, determine an expression for the velocity of the object as a function of time. (at t= 0, v=0)
Saturday, January 12, 2013 at 10:00pm

physics
an object's acceleration is given by the function a= 2/v^2, determine an expression for the velocity of the object as a function of time. (at t= 0, v=0)
Saturday, January 12, 2013 at 10:00pm

physics
Suppose the charge q2 in the figure below can be moved left or right along the line connecting the charges q1 and q3. Given that q = +15 µC, find the distance from q1 where q2 experiences a net electrostatic force of zero? (The charges q1 and q3 are separated by a fixed ...
Saturday, January 12, 2013 at 9:14pm

physics
A 1060 N crate is being pulled across a level floor by a force F of 300 N at an angle of 35° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate. answer in m/s2 if possible. ...
Saturday, January 12, 2013 at 9:02pm

Physics
A clerk moves a box of cans down an aisle by pulling on a strap attached to the box. The clerk pulls with a force of 188.0 N at an angle of 26° with the horizontal. The box has a mass of 30 kg, and the coefficient of kinetic friction between the box and the floor is 0.45. ...
Saturday, January 12, 2013 at 9:00pm

physics
A 3.40 kg block is pushed along the ceiling with an constant applied force of F = 82.0 N that acts at an angle θ = 50° with the horizontal, as in the figure below. The block accelerates to the right at 5.80 m/s2. Determine the coefficient of kinetic friction between ...
Saturday, January 12, 2013 at 8:59pm

physics
A box slides down a 26° ramp with an acceleration of 1.19 m/s2. Determine the coefficient of kinetic friction between the box and the ramp.μk =
Saturday, January 12, 2013 at 8:58pm

Physics
A 93 kg clock initially at rest on a horizontal floor requires a 614 N horizontal force to set it in motion. After the clock is in motion, a horizontal force of 510 N keeps it moving with a constant velocity. Find μs between the clock and the floor. Find μk between ...
Saturday, January 12, 2013 at 8:57pm

Physics
A 4.3 kg bag of groceries is in equilibrium on an incline of angle θ = 30°. Find the magnitude of the normal force on the bag.
Saturday, January 12, 2013 at 8:55pm

PHYSICS
Determine the normal force for a laundry basket with a mass of 5.8 kg in each of the following situations (a) at rest on a horizontal surface (b) at rest on a ramp inclined at 12° above the horizontal (c) at rest on a ramp inclined at 25° above the horizontal (d) at ...
Saturday, January 12, 2013 at 8:54pm

physics
A 0.155 kg baseball is thrown upward with an initial speed of 14.5 m/s. What is the force on the ball when it reaches half of its maximum height? (Disregard friction.) What is the force on the ball when it reaches its peak?
Saturday, January 12, 2013 at 8:52pm

Physics
Two forces are applied to a car in an effort to accelerate it, as shown below. The first force, F1 = 364 N, is applied at an angle α = 33° to the forward dashed line. The second force, F2 = 522 N, is applied at an angle β = 11° to the forward dashed line. ...
Saturday, January 12, 2013 at 8:50pm

physics
In what height the gravitational force with which earth exerts on any object in distance is 5 times smaller than the gravitational force,with which earth exerts in the same object when that object is on earth?
Saturday, January 12, 2013 at 8:16pm

physics
In what height the gravitational force with which earth exerts on any object in distance is 5 times smaller than the gravitational force,with which earth exerts in the same object when that object is on earth?
Saturday, January 12, 2013 at 7:29pm

physics PLEASE HELP
In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner?
Saturday, January 12, 2013 at 7:07pm

physics
A solid sphere of mass m and radius r rolls with out slipping along the track.it starts from rest with the lowest point of tthe sphere at aheight h above the bottom of the loop of radius R,much larger than r.(a) what is the minimum value of h (interms of R)such that the sphere...
Saturday, January 12, 2013 at 4:30pm

physics
a farmer drives a 0.100 kg iron spike with a 2.00 kg sledge hammer. the sledge hammer moves at a speed of 3.00 m/s and comes to rest on the spike after each swing. assuming all the energy is absorbed by the nail and ignoring the work by the nail, how much would the nails ...
Saturday, January 12, 2013 at 3:38pm

physics
an elevator motor provides 45 W of power while lifting a 2000 kg elevator 35 m. if the elevator contains six passengers of the same mass and it takes 20.0 to accomplish this task, determine pass of each passenger.
Saturday, January 12, 2013 at 3:35pm

physics
a 10kg toy mootorized boat uses 2.0 W of power, has a constant accel from rest and reaches a certain speed in 10 s on a horizontal surface. what was the final speed ?
Saturday, January 12, 2013 at 3:32pm

physics
A 500 g piece of silver at 150 degree Celsius is submerged in 1000 g of water at 5 degree Celsius to be cooled. determine the final temperature of silver and water given Cwater = 4.18 x 10 ^3 J/kg degree Celsius Csilver = 2.4 x 10^2 J/kg degree Celsius
Saturday, January 12, 2013 at 3:30pm

physics
a mechanic uses a chain and bloc pulley to lift a 875-kg engine 4.0 m to the top of the garage. the downward force on the chain over the 4.0 m distance is 5.0 x 10^4 N. a)calculate the work done in raseing the motor b)how much useful work was done c)what is the inefficiency of...
Saturday, January 12, 2013 at 3:24pm

physics
a 2.0 kg bad is held by a string to the ceiling . A 10 g bullet traveling at 200 m/s strikes the stationary bag. the height after the collision is 10.0 cm. assuming there is no friction, determine the speed, in meters per second, of the bag after the collisaon.
Saturday, January 12, 2013 at 3:21pm

physics
A 200.0 N force moves a 120.0 kg crate on a friction less surface from rest to final speed of 9.6 m/s. what is the displacement of the crate at the time it reaches this speed ?
Saturday, January 12, 2013 at 3:18pm

physics
a worker lays a rubber handled 0.500kg hammer down a sloped roof. it slides down the roof to a level portion of the roof where it slides another 2.oo m long this horizontal surface. the coefficient of friction between the rubber handle and the shingles is 0.850 a)draw free ...
Saturday, January 12, 2013 at 3:15pm

physics
sphere A has a mass of 4.2*10^-2 kg and is tethered to a wall by a thin thread. Sphere a has an excess of 1.2 *10^12 electrons. Sphere B has a deficit of 3.5*10^12 electrons and is o.23 m from sphere A a) determine the angle between the thread and the wall b) determine the ...
Saturday, January 12, 2013 at 12:59pm

physics
an electron with a mass of 9.11 x 10^-31 kg is accelerated from rest across a set of 150 V and are separated by 0.80 cm. a) determine the kinetic energy of the electron after it crosses between the plates.( ans 2.4 * 10^-17 j) b) determine the final speed of the electrons. (...
Saturday, January 12, 2013 at 12:53pm

physics
A block of mass 2 kg is connected to a freely hanging block of mass 4 kg by a light and inextensible string which passes over pulley at the edge of a table. The 2 kg mass is on the surface of the table assumed to be smooth. Calculate the acceleration of the system and the ...
Saturday, January 12, 2013 at 12:52pm

To rajesh jain
Do not post any question more than once. Currently, I don't see any physics tutors online. Please be patient and wait for them to find what you have already posted.
Saturday, January 12, 2013 at 12:39pm

Physics
The instruments attached to a weather balloon have a mass of 5.2 kg. The balloon is released and exerts an upward force of 98 n on the instruments. A)what is the acceleration of the balloon and instruments? B) after the balloon has accelerated for 10s, the instruments are ...
Saturday, January 12, 2013 at 12:40am

physics
You are driving a car 33 down the road. The stoplight in front of you suddenly turns red and you slam on the brakes, skidding to a halt. You get out of the car and measure the skid marks made by your tires to be 23.5 meters (Assume positive x to be in the forward direction) ...
Friday, January 11, 2013 at 4:16pm

Physics
A ball of mass m(1) = 0.250 kg and initial v(1) = 5.00 m/s collides head-on with a ball of mass m(2) = 0.800 kg that is initially at rest. What are the velocities of the balls after the collision if they stick together?
Friday, January 11, 2013 at 3:49pm

physics
An engine moves a motorboat through water at a constant velocity of 22 meters/second. If the force exerted by the motor on the boat is 5.75 × 103 newtons, what is the power of the motor?
Friday, January 11, 2013 at 3:27pm

Physics
For the problem (8.99 X 10^9 NM^2/c^2)(1 X 10^-6c) / (.1m)^2 = .90 N When I put this in my calculator I did not get .90N. Am I suppose to convert the units to get the answer. Thank you for your help.
Friday, January 11, 2013 at 2:58pm

Physics
Black Holes are suspected when a visible star is being noticeably pulled by an invisible partner that is more than 3 times as massive as the Sun. A red giant star is accelerated in a linear direction by gravity at 0.075 m/s2 towards an object that is 9.4 x1010 m away. a) What ...
Friday, January 11, 2013 at 12:48pm

Physics
The International Space Station is 370 km above the Earth's surface (Re = 6378 km, Me = 5.98 x 10^24 kg). What is the linear velocity of the space station in m/s
Friday, January 11, 2013 at 12:44pm

Physics
A point charge +6.7 uC is placed at the origin, and a second charge –3.6 uC is placed in the X - Y plane at (0.40 m , 0.55 m ). Where should a third charge be placed in the plane so that the net force acting on it is zero?
Friday, January 11, 2013 at 10:20am

physics
A 2kg and a 4kg hang freely at opposite ends of a light inextensible string which passes over a small and light pulley fixed to a rigid support calculate the acceleration of the system
Friday, January 11, 2013 at 9:52am

Physics
A 25.2-kg object is moving rightward across a horizontal surface with a speed of 14.3 m/s The coefficient of friction between the object and the surface is 0.490.
Thursday, January 10, 2013 at 10:44pm

physics
Spaceman Spiff's space box wights 60N. its engine exerts a +312N of force at lift-off. what is the acceleration when it lifts off
Thursday, January 10, 2013 at 10:19pm

Physics
A golf ball has a mass of 0.05 kg and acquires a speed of 80.0 m/s when hit with a force of 3000 N. how long was the club in contact with the golf ball?
Thursday, January 10, 2013 at 9:50pm

College Physics
The masses of the earth and moon are 5.98 × 1024 and 7.35 × 1022 kg, respectively. Identical amounts of charge are placed on each body, such that the net force (gravitational plus electrical) on each is zero. What is the magnitude of the charge placed on each body?
Thursday, January 10, 2013 at 9:17pm

Physics
A 2.2m of steel wire hangs vertically down from a support. A 1.5m length of brass wire of the same diameter is attached to the lower end of the steel wire.when a 10 kg mass is attached to the lower end of the brass wire a total extension of 0.05 m is produced. by how much does...
Thursday, January 10, 2013 at 8:56pm

physics PLEASE HELP
In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner?
Thursday, January 10, 2013 at 8:48pm

physics PLEASE HELP
A tiny ball (mass = 0.015 kg) carries a charge of -19C. What is the electric field magnitude that would cause the ball to float above the ground?
Thursday, January 10, 2013 at 8:46pm

Physics
An object was fired with an initial speed of 33m/s at an angle of 32 degrees from the horizontal. How long was it in the air?
Thursday, January 10, 2013 at 8:45pm

physics
A toy top consists of a rod with a diameter of 13.00 mm and a disk of mass 0.0160 kg and a diameter of 3.5 cm. The moment of inertia of the rod can be neglected. The top is spun by wrapping a string around the rod and pulling it with a velocity that increases from zero to 3.0 ...
Thursday, January 10, 2013 at 7:34pm

physics
A hard drive on a modern computer spins at 10000 rpm (revolutions per minute). If the driver is designed to start from rest and reach operating speed in 1.4 s, what is the angular acceleration of the disk?
Thursday, January 10, 2013 at 7:32pm

physics
A laboratory ultracentrifuge is designed to produce a centripetal acceleration of 4.0 106 g at a distance of 5.00 cm from the axis. What angular velocity in rev/min is required?
Thursday, January 10, 2013 at 7:32pm

physics
A bicycle wheel with a radius of 38 cm is given an angular acceleration of 2.61 rad/s2 by applying a force of 0.45 N on the edge of the wheel. What is the wheel's moment of inertia?
Thursday, January 10, 2013 at 7:31pm

physics
A toy consisting of two balls, each m = 0.56 kg, at the ends of a l = 0.73 m long, thin light-weight rod is shown below. Find the moment of inertia of the toy. The moment of inertia is to be found about the center of the rod.
Thursday, January 10, 2013 at 7:29pm

physics
You generate a wave in a spring, stretched out on the floor, by oscillating your hand back and forth at a frequency of 1.6 Hz. The wave has a 1.5-m wavelength. If the wave takes 2.9 s to travel to the other end of the spring and back to your hand, what is the length of the ...
Thursday, January 10, 2013 at 6:50pm

Physics THRUST
To begin I just need to know how to do thrust. A lunar lander in powered descent at 100 m above the surface of the moon slows down from a velocity of 20 m/s to 0.5 m/s at constant acceleration. Assume that the lander has a mass of 20,000 kg and that burning the fuel does not ...
Thursday, January 10, 2013 at 3:24pm

physics
A 2.2 kg rock initially at rest loses 412 J of potential energy while falling to the ground. Assume that air resistance is negligible. Calculate the kinetic energy that the rock gains while falling. What is the rock's speed just before it strikes the ground?
Thursday, January 10, 2013 at 3:23pm

physics
A 17 kg rock, m, is on the edge of a 105 m cliff, h, as shown in Figure 11-20. Assume that air resistance is negligible. What speed does the rock have as it strikes the ground?
Thursday, January 10, 2013 at 3:17pm

physics
How much potential energy does DeAnna with a mass 57.0 kg, gain when he climbs a gymnasium rope a distance of 3.7 m?
Thursday, January 10, 2013 at 3:02pm

Physics
You place two charges a distance r apart. Then you double each charge and double the distance between the charges. How does the force between the two charges change? a) The new force is twice as large. b) The new force is half as large. c) The new force is four times as large...
Thursday, January 10, 2013 at 12:42pm

physics
Does this question even make sense: A 7900 kg helicopter carrying a 1100 kg load is accelerating upwards at 1.2 m/sec squared. What is the force of air resistance pushing down on the helicopter?
Thursday, January 10, 2013 at 12:00pm

Physics
A 75.0kg bobsled is pushed along a horizontal surface by two athletes. After the bobsled is pushed a distance of 4.5m starting from the rest, its speed is 6.0m/s. Find the magnitude of the net force on the bobsled.
Thursday, January 10, 2013 at 11:16am

physics
The mass of a string is 2.5 × 10-3 kg, and it is stretched so that the tension in it is 250 N. A transverse wave traveling on this string has a frequency of 300 Hz and a wavelength of 0.45 m. What is the length of the string?
Thursday, January 10, 2013 at 10:46am

Physics
An electron with a mass of 9.11 *10^31 Kg is accelerated from rest across a set if parallel plates that have a potential difference of 150 v and are separated by 0.80 cm A) determine the kinetic energy of the electron after it crosses between the plates. (Ans 2.4 * 10-17 ) B) ...
Thursday, January 10, 2013 at 8:59am

Physics
An electron with a horizontal speed of 4.0 * 10^6 m/s and no vertical component of velocity passes through two horizontal parallel plates. The magnitude of the electric field between the plates is 150 n/c the plates are 6.0 long A) calculate the vertical component of the ...
Thursday, January 10, 2013 at 8:45am

Physics
An electron with a horizontal speed of 4.0 * 10^6 m/s an no vertical component of velocity passes through two horizontal plates. The magnitude of the electric field between the plates is 150 n/c. The
Thursday, January 10, 2013 at 8:38am

physics
A girl goes 4 avenues east{.8 miles), then 24 streets south(1.2 miles), the n 1 avenue west(.2 miles), and finally 8 streets north(.4 miles). -what distance did she travel? -what is her resultant displacement?
Thursday, January 10, 2013 at 1:50am

physics
Sir Lost-a-Lot dons his armor and bursts out of the castle on his trusty steed Tripper in his quest to rescue fair damsels from dragons. Unfortunately his valiant aide Doubtless lowered the drawbridge too far and finally stopped it 28 ◦ below the horizontal. Losta-...
Thursday, January 10, 2013 at 1:38am

PHYSICS HEL ME ......................JORHO........
The “Vomit Comet.” In Zero-gravity astronaut training equipment testing, NASA flies a KC135A aircraft along a parabolic flight path. As shown in Figure P4.47, the air-craf climbs from 24000ft to 31000ft,where it enters a parabolic path with a velocity of ...
Wednesday, January 9, 2013 at 11:30pm

PHYSICS 1 ..'''''''''''''''''''''''' helllpppppppp
The “Vomit Comet.” In Zero-gravity astronaut training equipment testing, NASA flies a KC135A aircraft along a parabolic flight path. As shown in Figure P4.47, the air-craf climbs from 24000ft to 31000ft,where it enters a parabolic path with a velocity of ...
Wednesday, January 9, 2013 at 11:25pm

physics
A lunar lander in powered descent at 100 m above the surface of the moon slows down from a velocity of 20 m/s to 0.5 m/s at constant acceleration. Assume that the lander has a mass of 20,000 kg and that burning the fuel does not change the mass. Answer the following questions...
Wednesday, January 9, 2013 at 8:43pm

physics
A lunar lander in powered descent at 100 m above the surface of the moon slows down from a velocity of 20 m/s to 0.5 m/s at constant acceleration. Assume that the lander has a mass of 20,000 kg and that burning the fuel does not change the mass. Answer the following questions...
Wednesday, January 9, 2013 at 8:40pm

Basic Physics
What is the force of gravity between two spheres that have a mass of 8 kg and are separated by 27 m?
Wednesday, January 9, 2013 at 8:23pm

physics
A ceiling fan is rotating 245 times each minute. What is its frequency? What is its period of rotation? What is its angular velocity? When the fan is turned off, it slows down at 2.50 rad/s2 – how long will it take the fan to stop?
Wednesday, January 9, 2013 at 7:55pm

physics
A playground seesaw is exactly 3.00 m long. A little girl who weighs 425 N is sitting on one end. If a little boy weighing 575 N wants to sit on the other side, how far must he sit from the fulcrum to keep the seesaw perfectly balanced?
Wednesday, January 9, 2013 at 7:21pm

physics
A girl delivering newspapers travels 3 blocks west, 4 blocks north, then 6 blocks east. What is her resultant displacement? what is the total distance that she travelled? and how do I graph this??
Wednesday, January 9, 2013 at 7:04pm

PHYSICS HELP
Back in the stage coach era, iron rims were placed on wooden wheels by shrink-fitting. Suppose that the wheel has a diameter of 100.00 cm, whereas the rim has an inside diameter if 99.75 cm at 20°C. How hot must the iron rim be heated if it is to be slid over the wheel? (...
Wednesday, January 9, 2013 at 5:16pm

physics
if a car moving 180km/h reduces to 72km, what is the percentage change in kinetic energy?
Wednesday, January 9, 2013 at 4:41pm

physics 101
At what temperature is the root mean square speed of oxygen molecules equal to the root mean square speed of hydrogen at 27 degrees?
Wednesday, January 9, 2013 at 4:25pm

Physics
A U.S. resident traveling in Japan notices that the temperature in degrees F is easily calculated to be 3.7 times the temperature in degrees C. What is the temperature in degrees F?
Wednesday, January 9, 2013 at 2:52pm

Physics
By what amount will a 178 m long concrete slab on the Mackinac Bridge contract when going from +39C to -35C? The linear expansion coefficient is 10-5 per C.
Wednesday, January 9, 2013 at 2:19pm

Physics
A closed organ pipe has a fundamental frequency of 380 Hz at 30C. What would be its next higher resonant frequency at 18C?
Wednesday, January 9, 2013 at 12:43pm

Physics
A stationary whistle emits a sound of 188 Hz. If passengers in a car hear the whistle with a frequency of 198 Hz, how fast was the car moving? Use 340 m/s for the sound velocity
Wednesday, January 9, 2013 at 12:41pm

physics
A batted baseball, which leaves the bat at an angle 〖30〗^0 above the horizontal, is caught by an outfielder 120m from the plate. a.) What is the initiated velocity of the ball? b.) How high did it rise? c.) How long was it in the air? my friend asked that ...
Wednesday, January 9, 2013 at 8:53am

physics
object a does a freefall motion from an 80-m building and object b thrown upward from the base at the same time. they collide after 2s. find the initial velocity of object b. height is 80 m.
Wednesday, January 9, 2013 at 7:50am

physics
block a in figure 1 has a mass of 10kg, and block b has a mass of 30 kg. the coefficient of friction between b and the horizontal surface is 0.3. a) what is the mass of block c if block b is moving with an acceleration of 3m/s/s b) what is the tension in each cord when b is ...
Wednesday, January 9, 2013 at 7:43am

physics
block a in figure 1 has a mass of 10kg, and block b and the horizontal surface is 0.3. a) what is the mass of block c if block b is moving with an acceleration of 3m/s/s b) what is the tension in each cord when b is moving with a constant velocity?
Wednesday, January 9, 2013 at 7:35am

Physics
a car is moving at 100 km/hr is 0.5 km behind another car moving at 60 km/h how far does the first car travel before it catches the second car?
Wednesday, January 9, 2013 at 6:06am

Physics
an archer released an arrow at the speed of 29 km/hr. after one second another arrow was released at the same direction, will the arrows meet?
Wednesday, January 9, 2013 at 6:00am

Physics
a circular disc rotates on a thin air film with a period of 0.3s. its moment of inertia about its axis of rotation is 0.06kgm^2. a small mass is dropped onto th disc and rotates with it . the moment of inertia of the mass about the axis of rotation is 0.04kgm^2.determine the ...
Wednesday, January 9, 2013 at 3:40am

Physics
Suppose a large dump truck tire has a surface area of 26.3 m^2. If a force of 1.58×10^7 Newtons acts on the inner tire, what is the absolute pressure inside the tire? What is the gauge pressure on the tire's surface?
Wednesday, January 9, 2013 at 12:30am

Physics
Suppose a large dump truck tire has a surface area of 26.3 m^2. If a force of 1.58×10^7 Newtons acts on the inner tire, what is the absolute pressure inside the tire? What is the gauge pressure on the tire's surface?
Wednesday, January 9, 2013 at 12:29am

Physics
A car's brake system transfers pressure from the main cylinder to the brake shoes on all four wheels. The surface area of the main cylinder piston is 7.2 sq cm, and that of the piston in each individual brake cylinder is 1.80 sq cm. The driver exerts a 5.00 N force on the...
Wednesday, January 9, 2013 at 12:12am

Physics
The period of Mars' rotation is 24 hours, 37 minutes, and 23 seconds. At what altitude above Mars would a "Mars-stationary" satellite orbit?
Wednesday, January 9, 2013 at 12:04am

Physics
Car A is traveling at 18 m/s and car B at 25 m/s. Car A is 300m behind car B when the driver of Car A accelerates his car with an acceleration of 1.80m/s^2. How long does it take car A to overtake car B?
Tuesday, January 8, 2013 at 9:25pm

physics
A 4.75 mass was dropped from a certain height and achieved a maximum velocity of 7.68 m/s just before striking the ground. Determine the height from which the mass was dropped. Ignore air drag.
Tuesday, January 8, 2013 at 9:14pm

Physics
The New England Merchants Bank Building in Boston is 152 high. On windy days it sways with a frequency of 0.12 , and the acceleration of the top of the building can reach 2.5 of the free-fall acceleration, enough to cause discomfort for occupants. What is the total distance, ...
Tuesday, January 8, 2013 at 8:16pm

PHYSICS HELP PLEASE!
A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the baseball’s initial velocity is 12.0 meters per second. What is the magnitude of the ball’s initial velocity?
Tuesday, January 8, 2013 at 8:04pm

Physics ASAP PLEASE
A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the baseball’s initial velocity is 12.0 meters per second. What is the magnitude of the ball’s initial velocity?
Tuesday, January 8, 2013 at 7:47pm

Physics
The sun has a mass of 1.99x10 30 kg the earth has a mass of 5.98x10 24 kg and is 1.496x10 11 m from the sun a) Calculate the force of gravity acting on the eaarth by the sun b) CAlculate the force of gravity acting on the sun by the earth
Tuesday, January 8, 2013 at 7:42pm

physics
If A = 4 units north, B = 4 units east, and C = 6 units northeast (45o east of north), click on the figure to find A + B + C. Construct the figure.
Tuesday, January 8, 2013 at 7:26pm

Physics
The New England Merchants Bank Building in Boston is 152 high. On windy days it sways with a frequency of 0.12 , and the acceleration of the top of the building can reach 2.5 of the free-fall acceleration, enough to cause discomfort for occupants. What is the total distance, ...
Tuesday, January 8, 2013 at 4:59pm

Physics
A lawn roller is pushed across a lawn by a force of 119 N along the direction of the handle, which is 22.5° above the horizontal. If 65.7 W of power is developed for 90.0 s, what distance is the roller pushed?
Tuesday, January 8, 2013 at 4:15pm

Physics
A 492g oscillator has a speed of 99.5 cm/s when its displacement is 3.60 cm and 72.5 cm/s when its displacement is 5.10 cm. What is the oscillator's maximum speed? I'm suck with this problem, can someone please go through it with me step by step, please and thanks
Tuesday, January 8, 2013 at 2:47pm

Physics, science
A sonar generator on a ship produces periodic ultrasonic waves at a frequency of 2.2 MHz. The wavelength of the waves in seawater is 5.310-4 m. When the generator is directed downward, an echo is received 15.2 s later. How deep is the ocean in m?
Tuesday, January 8, 2013 at 2:43pm

Physics, waves
A string vibrates in its fundamental mode with a frequency of 200 Hz. The string is 0.64 m long and has a mass of 1.61 g. With what tension must the string be stretched?
Tuesday, January 8, 2013 at 2:41pm

science, physics
A block of mass 0.25 kg is connected to a spring with spring constant 35 N/m. The block is oscillating on a frictionless horizontal surface. Its speed as it passes through its equilibrium position is 1.04 m/s. What's the total energy of the system?
Tuesday, January 8, 2013 at 12:52pm

Physics
A 0.46 kg mass oscillates in simple harmonic motion on a spring that has a spring constant of 2080 N/m. The spring was initially compressed 9.4 cm (a negative displacement) at t = 0 s. What's the velocity in m/s of the mass at t = 0.24 s?
Tuesday, January 8, 2013 at 12:34pm

Physics,
A block of mass 0.25 kg is connected to a spring with spring constant 35 N/m. The block is oscillating on a frictionless horizontal surface. Its speed as it passes through its equilibrium position is 1.04 m/s. What's the total energy of the system?
Tuesday, January 8, 2013 at 12:25pm

AP Physics
Momentum One of those Civil War cannons is fired. The Cannon has a mass of 873kg It fires a 35.0kg cannon ball at a velocity of 145 m/s at an elevation angle of 35.0 degrees. The length of the barrel is 2.10m. (a) What is the recoil velocity of the cannon?(b)What is the KE of ...
Tuesday, January 8, 2013 at 3:10am

Physics
A 492g oscillator has a speed of 99.5cm/s when its displacement is 3.60cm and 72.5cm/s when its displacement is 5.10cm . What is the oscillator's maximum speed? (units cm/s)
Tuesday, January 8, 2013 at 2:31am

physics
What is k in the formula (3/2)kT
Monday, January 7, 2013 at 11:21pm

physics
What is k in the formula (3/2)kT
Monday, January 7, 2013 at 11:20pm

Physics
A train travels east at a speed of 50 m/s. A passenger is walking towards the rear of the train at a speed of 3 m/s. Assume that you are standing at the train station and observing the motion of the passenger as the train passes you at the station. What is the velocity of the ...
Monday, January 7, 2013 at 10:53pm

Physics
A 0.200 kg block of ice at -15 degrees Celsius is placed into a pan on a stove, heated to a liquid, and then to vapour with a final temperature of 115 degrees Celsius. Calculate the total amount of heat required for this process.
Monday, January 7, 2013 at 5:42pm

Physics-Momentum
Baseball 0.14 kg moving at 35 m/s. Momentum of the ball? this should be easy b/c i know p=m*v but i get 4.9 kgm/s and it's wrong.....
Monday, January 7, 2013 at 4:45pm

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