Work and Power

When is work done on an object?

What two things must happen to do work on an object?

How is energy transmitted to a bowling ball to make it move down the alley?

In the figure, there are four examples. For each example, decide if work is being done and write your answers in the figure.

How much work is done pushing a car 20 m with a force of 300 N? Show your work.

In the last figure, a barbell weighing 80 N is lifted 2 m off of the ground. How much work is done? Show your work.

Suppose it takes the same amount of work for two people to move an object. One person applies less force in moving the object than the other. How can they both do the same amount of work?

An escalator and an elevator can transport a person from one floor to the next. The escalator does it in 15 s and the elevator takes 10 s. Which does more work on the person? Which has the greater power output?

A light bulb is on for 12 s, and during that time it uses 1,200 J of electrical energy. What is the wattage (power output) of the light bulb?

Why does the electric sander have a higher power output than sanding by hand?