"Two bodies of masses 5 and 7 kilograms are initially at rest on a horizontal frictionless surface. A light spring is compressed between the bodies, which are held together by a thin thread. After the spring is released by burning through the thread, the 5 kilogram body has a speed of 0.2 m/s. The speed of the 7 kilogram body is (in m/s)"

A 75 kg bicyclist is traveling with some speed. She approaches a hill that is 56 m high. How fast must she be biking to make it to the top of the hill and still be moving 1 m/s?

What mass of butter, which has a usable energy content of 6.0 Cal/g (= 6000 cal/g), would be equivalent to the change in gravitational potential energy of a 56 kg man who climbs 8.40 km? Assume that the average g for the climb is 9.80 m/s2.

An object of mass m = 2.9 kg is free to move on a horizontal surface without any friction. It is initially at rest and starts moving under a net force of F = (3N)i + (4N)j. What is the object's speed in m/s after moving 1 meter?

After coming down a slope, a 60-kg skier is coasting northward on a level, snowy surface at a constant 15 m/s. Her 5.0-kg cat, initially running southward at 3.8 m/s, leaps into her arms, and she catches it. (a) Determine the amount of kinetic energy converted to internal energy in the Earth reference frame. (b) What is the velocity, measured in the Earth reference frame, of an inertial reference frame in which the cat's kinetic energy does not change?..

A toy car of mass m is pushed along a frictionless track so that it is moving at a speed v1- It hits a spring with stiffness k at the end of the track causing the spring to compress. What is the maximum compression x of the spring? By conservation of energy, K1 + Uj = K2 + U2 Some of the terms in the equation above are zero; thus it can be simplified to: %3D 2 = ½ ½m Isolating the compression x, x = ( 2 1/2 Suppose the mass of the toy car moving at 2.5 m/s is 0.0505 kg and the spring constant is k = 605 N/m, the spring will experience a maximum compression of 0.0 84 m.

While running, a person dissipates about 0.600 J of chemical energy to mechanical energy per step per kilogram of body mass. If a 75.0 kg runner dissipates energy at a rate of 83.0 W during a race, how fast is the person running? Assume a running step is 1.50 m long.

A 58-kg diver is standing on a platform that is 35 meters above the surface of the water. He steps off the platform with zero initial velocity and descends toward the water below. Assuming that no energy is lost to his surroundings, how much kinetic energy (in joules) does the diver have right before he hits the water?

A collision cart on a flat track is launched using a compressed internal spring. The cart has a mass of 0.5 kg and the spring is compressed 0.03 m. If the spring constant is 270 N/m, how much speed will the cart have when the spring is released? (No friction) O 7 m/s O 5 m/s O 0.5 m/s 0.7 m/s

Brad tries out a weight-loss plan that involves repeatedly lifting a 44.2-kg barbell from the floor over his head to a height of 2.00 m. If he is able to complete three such lifts per minute, how long will it take for him to lose 0.50 kg of fat? “Burning” 1 g of fat supplies 38.8 kJ to the body; of this, 10.0% can be used by the muscles to lift the barbell. (Ignore the fat “burned” while he lowers the barbell to the floor.)