Work and Power

Hello!

You Need: Pencil Science Notebook Science Folder Calculator Drawing from Fri

Everything else goes into the corners of the room.

Bell Work:

Open your science notebook to a new page. Title the page “Work.” Answer the question below.As a student your

teacher expect you to go home and do homework. Are you really doing work? Why or Why not?

To Do Work: You Need 2 Things

A Force – A push or a pull on something. Push a chairPull your

notebook off a desk.

Other examples?

Motion – Movement

Measured in miles

KilometersMetersOther

examples?

Force is necessary to do work.

Work: The use of force to move an object some distance.

In order for work to happen, we have to have the following: Force Motion Motion in the direction of the force

If one of those three things is not present, then no work is being done.

Bell Work Answer

You are doing homework. Is there force? Is there motion? Is the movement in the direction of the force?

Discuss with a neighbor if doing your homework is actually “Work.”

Rotating Lab Stations

Label your paper 1-4, skipping two lines in between numbers.

Go to your assigned lab station. You need your notebook and a pencil. With your group, decide if the picture on your

station is doing work. If it is doing work explain, why? If it is not doing

work, explain what characteristic is missing.

You will be moving around to all 4 lab tables.

Number 1 – Picking a chair up and walking

forward

Force

Motion

Number 2 – Mr. Feeny at his office

Number 3 – Picking a weight up above your head

Force

Motion

Number 4 – Pushing a lawnmower.

Force

Motion

Calculating Work

Work is a measure of how much force is applied over a certain distance.

The formula for finding the amount of work done is below:

W= Force x Distance

W=FxD

Other Equations

W

FD

Work = Force x Distance

Force = Work / Distance

Distance = Work / Force

Units

The formula for work is W=FxD

What is being measured?

Unit

Force Newton (N)

Distance Meter (M)

Work Newton x Meter or Joule (J)

Calculations Practice

W?

F = 10 N

D = 5 M

W=FxD

W= 10N x 5M

W= 10 x 5

W= 50 J

Calculations Practice

W?

F = 12N

D = 9M

W=FxD

W=12N x 9M

W= 12 x 9

W= 108 J

Calculations Practice

W18 J

F = ?

D = 3M

Force = Work/Distance

Force = 18 J / 3 M

F= 18/3

F= 6N

Review

A body builder lifts 350 pounds above his head. Is any work done?A. YesB. No

Review

A body builder lifts 350 pounds above his head. Is any work done?A. Yes

Review

A scientist delivers a speech to an audience of his peers. Is work done?A. YesB. No

Review

A scientist delivers a speech to an audience of his peers. Is work done?B. No

Review

If a man pushes a concrete block 10 meters with a force of 20 N, how much work has he done? A. 200 N B. 150 J C. 200 J D. 150 N

Review

If a man pushes a concrete block 10 meters with a force of 20 N, how much work has he done? C. 200 J