A large hoist is lifting a 2000 kg automobile. There is a gauge on the hoist that displays its power consumption, and itreads 13, 720W. It takes 10 s to lift the car. A. How much energy did it take to lift the car? B. How high did the hoist lift the car?

In the figure, the rock weighs 215 lb and is lifted 1 ft by the lever. A. How much work is done in ft-lb? B. The other end of the lever is pushed down 3 ft while lifting the rock. What force had to act on that end in lb?

5. Joseph sweeps his sidewalk with a broom. Joseph performs 42 Joules of work pushing dead leaves with the broom with a force of 18 N. Calculate the distance that Joseph pushed the dead leaves. Report your answer in meters. 6. A tractor pulls a hay wagon with a force of 430 N. The tractor performs 760,000 Joules of work. Calculate the distance that the tractor pulled the wagon. Report your answer in meters. 7. A tractor pulls a hay wagon a distance of 1300 meters. The tractor performed 260,000 Joules of work. Calculate the force that the tractor used to pull the wagon. Report your answers in Newtons.

A freight elevator weighs 6200 N. What is the power required to raise the elevator a. What a distance of 20 meters in 10 seconds? b. One of the motors for the freight elevator system goes out. Now the maximum power available to move the 6200 N freight elevator is 10 kW. How long does it take to raise the elevator 20 meters now?

036. A 1.50 kg model train initially traveling at 0.50 m/s acceler- ates to 1.00 m/s in 10. s. a. What is the change in the train's kinetic energy? b. How much power was expended to accelerate the train?

A machine has a power rating of 300 watts. It worked for 4.0 seconds. How much work was done? A. 75 J B. 1200 J C. 304 J

17. The kinetic energy of an 1800-kg truck is 7.2 x 105 J. What is the speed of the truck? A) 25 m/s B) 33 m/s C) 28 m/s 17 m/s E) 21 m/s

Which of the following statements are TRUE? A. Energy is a vector physical quantity. B. Energy is always required to do work. C. Totol mechanical energy can never be zero. D. When law of conservation of mechanical energy is invoked, there can never be a waste energy in an ideal system. E. When law of conservation of mechanical energy is invoked, there can never be a waste energy in a real-world system. F. Kinetic energy can be negative. G. Potential energy can be negative. H. Work is equivalent to the negative change in kinetic energy. I. Work is equivalent to the negative change in potential energy. J. In a conservative system where only gravitational force acts, the total mechanical energy is constant at every point of the motion. K. In a non-conservative system where certain external forces may act, the total mechanical energy is not constant at every point of the motion. L The entire universe may be considered as a closed system where the total energy is constant. chnices O B. D.…

An object that measured a mass of 0.89 kg started moving at a speed of 3.89 m/s. After some time, the speed increased to 6.25 m/s. What was the kinetic energy when the object reached the higher speed? b. What was the net work done by the object?

How much power is expended if you lift a 50 N rock 10 m in 2 seconds? A.250 W B.25 W C.2.5 W D.5 W