A running 51-kg cheetah has a top speed of 31 m/s.  (a) What is the cheetah's maximum kinetic energy? (b) Find the cheetah's speed when it's kinetic energy is one half of the value found in part (a)

A person drops a brick from the top of a building. The height of the building is 400.0 m and the mass of the brick is 1.70 kg. (a) Calculate the potential energy (in J) at the top of the building.  J (b) Calculate the speed of the brick right before it touches the ground.  m/s

A 0.800-kg particle has a speed of 2.10 m/s at point  and kinetic energy of 7.80 J at point . (a) What is its kinetic energy at ?(b) What is its speed at ?(c) What is the net work done on the particle by external forces as it moves from  to ?

A car of mass 800.0 kg accelerates away from an intersection on a horizontal road. When the car speed is 39.6 km/hr (11.0 m/s), the net power which the engine supplies is 3900.0 W (in addition to the extra power required to make up for air resistance and friction). Calculate the acceleration of the car at that time.

A man of mass 79.5 kg walks down the aisle of an airplane at a speed of 1.50 m/s in the forward direction while the plane moves at a speed of 325 m/s relative to the earth. (a) Find the man's kinetic energy relative to the plane.(b) Find the man's kinetic energy relative to the earth.

A pendulum consists of a 1.2 kg stone swinging on a 4.2 m string of negligible mass. The stone has a speed of 8.3 m/s when it passes its lowest point. (a) What is the speed when the string is at 56" to the vertical? (b) What is the greatest angle with the vertical that the string will reach during the stone's motion? (c) If the potential energy of the pendulum-Earth system is taken to be zero at the stone's lowest point, what is the total mechanical energy of the system? (a) Number i Unit (b) Number i Unit (c) Number i Unit

At NASA's Zero Gravity Research Facility in Cleveland, Ohio, experimental payloads fall freely from rest in an evacuated vertical shaft through a distance of 132 m. (a) If a particular payload has a mass of 28 kg, what is its potential energy relative to the bottom of the shaft? (b) How fast will the payload be traveling when it reaches the bottom of the shaft? Convert your answer to mph for a comparison to highway speeds.

A ball is dropped from a height at which it has 20 J of potential energy. How much kinetic energy does the ball have just before hitting the ground? (Assume the ground is at h = 0.)