Work

Lifting books out of your backpack? Carrying your backpack to class?

Pushing a car that is stuck in the snow?

Rolling a bowling ball?

What is Work?

Is this cat doing work?

Work is done on an object when the object moves in the same direction in which the force is exerted.

What is Work?

Sometimes force is applied to an object, but no work is

done.

If you push on a block and it doesn’t move, you have not

done ANY work in the scientific sense.

Which force is most likely to do

work on the block?

Work is done by forces over a distance. Work is done on objects. When force is measured in newtons and

distance in meters the SI unit for work is the newton*meter

A newton*meter is called a Joule

Calculating Work

To calculate work, you multiply the force by the distance the object moves in the direction of the force.

Calculating Work

How much work is done if the block is raised 3 meters?

Force (F)= 50 N distance (d)= 0.5 m

How much work is done on a 10-newton block that is lifted 5 meters off the ground by a pulley?

Practice Time!