Work

What is work?

In science, the word work has a different meaning than you may be familiar with.

The scientific definition of work is: using a force to move an object a distance (when both the force and the motion of the object are in the same direction.)

Work is the transfer of energy through motion.

Using your board: determine if the follow statement is work or not work and why..

A scientist delivers a speech to anaudience of his peers.

A body builder lifts 350 pounds above his head.

A mother carries her baby from room to room.

A father pushes a baby in a carriage.

A woman carries a 20 kg grocery bag to her car?

Work = Force x distance

The unit of force is newtons

The unit of distance is meters

The unit of work is newton-meters

One newton-meter is equal to one joule

So the unit of work is a joule

Formula for Work

W=Fd

Work = Force x Distance

w = F d

Work = Force x Distance

Calculate: If a man pushes a concrete block 10 meters with a force of 20 N, how much work has he done?

w=FdW = 20N x 10m

Check for Understanding

1. A weight lifter lifts a 500-N weight a distance of 2 m from the floor to a position over his head. How much work does he do?

Explain your answers.

F = 500 N

Distance = 2m

Work = Force x Distance

W = F x d

W = 500 N x 2 m =

The work that the weight lifter does is ________ Joules.