14-4: What is work?

14-4: What is work?

Not homework, or working a job!

Multiple Select

Which of the following has a lot of energy?

• A ball moving super fast

• A book really high in the air

• A pencil just sitting there

Multiple Choice

A kicker kicks a football and it goes flying.

Did the football gain energy?

• No

• Yes

What is work?

Work is done when a force moves an object over a distance. There needs to be a force, and an object needs to move.

What is work?

• work = force x distance

• We measure work in joules (J)

Multiple Choice

What other thing do we measure in joules?

• Mass

• Distance

• Energy

Energy and Work

• We said energy was the ability to make something happen.

• We can ALSO say energy is the ability to do work.

Work and Direction

• For work to happen, the force must make an object move in the same direction

• If they aren't in the same direction, then no work happens, even if it feels like it!

Multiple Choice

Mr. Austin holds up their Chromebook for 10 minutes. Did they do work?

• Yes

• No

Any questions?

• Next, we'll have a few review questions.

• Does anybody have any questions?

Multiple Choice

Work is only done if something is...

• stationary

• moving

• burning

Multiple Choice

TRUE or FALSE: For work to be done, the force must be in the same direction as the direction the object moves.

• True

• False

Multiple Select

Choose all situations where work is being done.

• Somebody holds a heavy package for one hour

• A football player kicks a field goal

• A tennis player hits a tennis ball over the net

Poll

How well do you think you understand today's topic?

• Really well!

• Kind of.

• I'm so confused...