A rifle with a barrel length of 56cm fires a 12g bullet with a horizontal speed of 350m/s . The bullet strikes a block of wood and penetrates to a depth of 10cm. what force does the block put on the bullet in newtons?

a light ray yhat is incident on air/glass interface.(n-glass=1.52& n-air=1)1.what is the angle of incident. 2.angle of refraction. 3.angle of incident inside. 4.angle of rafractoin ountside.5.the magnitude of the incident angle that will bring about no refraction inside

A car starts from rest at a stop sign. It accelerates at 4.1 for 7.0 , coasts for 1.7 , and then slows down at a rate of 2.6 for the next stop sign

Two workers push a 77kg crate to the right. With a force of 250N. The coeficient of friction is 0.29. What is the acceleration.

A 55.0 kg girl weighs herself by standing on a scale in an elevator. What is the force exerted by the scale when the elevator is descending at a constant speed of 10 m/s?

A refrigerator has an energy efficiency ratio (EER) of 7. For each unit of input energy (W), drawn from the electric power company, how many units of heat energy (Qhot) are dumped to the kitchen?

On a spacecraft two engines fire for a time of 535 s. One gives the craft an acceleration in the x direction of ax = 5.10 m/s2, while the other produces an acceleration in the y direction of ay = 7.30 m/s2. At the end of the firing period, the craft has velocity components of vx = 3835 m/s and vy...

One mole of air at 350 K confined in a cylinder under a heavy piston occupies a volume of 6.1 L. The heat capacity of air under constant volume is (5/2)R. Find the new volume of the gas if 3.9 kJ is transferred to the air. Answer in units of L.

A person in a car travelling at 30 ms-1 has a mass of 80kg. how much work does the person do against the braking force on him before stopping?

A student (m = 66 kg) falls freely from rest and strikes the ground. During the collision with the ground, he comes to rest in a time of 0.04 s. The average force exerted on him by the ground is +18000 N, where the upward direction is taken to be the positive direction. From what height did the...