B Power refers to the rate at which work is done. C Work involves a force acting upon an object to cause a displacement. The equation can be used for these two motions to find the work. A 50 kg sack is lifted 2 meters in the same time as a 25 kg sack is lifted 4 meters. The power is the rate at which work is done.
Power is found by dividing work by time.
Thus, the power is the same for both tasks. A TV set is pushed a distance of 2 m with a force of 20 N that is in the same direction as the set moves. It takes 40 J to push a large box 4 m across a floor. Using 1000 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. The momentum change can also be found if the force and the time are known.