Work, Power, and Simple Machines NOTES

Math Response

A book weighing 1.0 Newton is lifted 2 meters. How much work was done?​

W = Fd​

W = 1.0 N x 2 m​

W = _._ J

Type answer here

Correct Answer: 2.0

Deg^°

Rad

Multiple Select

A force of 15 Newtons is used to push a box a distance of 3 meters. How much work was done?

Select the correct equation and solution.

• 15 N x 3 m​

• 15 N ÷ 3 m

• 45 J

• 5 J

Multiple Choice

The robot pushes the box with a force of 30 Newtons to move the box a distance of 8 meters.

How much work did the robot do in moving the box?

• 3.75 Joules

• 38 Joules

• 240 Joules

Math Response

What is the power of a kitchen blender if it can perform 3,750 Joules of work in 15 seconds?​

P = W/t​

P = 3,750 J / 15 s

P = ___ watts

Type answer here

Correct Answer: 250

Deg^°

Rad

Multiple Select

A small motor does 4000 J of work in 20 seconds. What is the power of the motor in watts?

Select the correct equation and solution.

• 4000 J x 20 s

• 4000 J ÷ 20 s

• 80,000 W

• 200 W

Match

Type the variable to its unit of measurement

• work

• power

• force

• time

• distance

Joules (J)

watts (W)

Newtons (N)

seconds (s)

meters (m)

• Joules (J)

• watts (W)

• Newtons (N)

• seconds (s)

• meters (m)

Match

Try to match the simple machine to it example:

• pulley

• lever

• wheel and axle

• screw

• inclined plane

elevator

seesaw

bicycle

light bulb

ramp

• elevator

• seesaw

• bicycle

• light bulb

• ramp

Multiple Choice

In the PhET Force & Motion simulation, the box will come to a rest after the robot stops pushing. Why do you think the boxes would stop moving?

• The robot exerts too much force on the boxes.

• There is surface friction opposing motion.

• The robot did not push far enough.

Multiple Choice

Friction is a force that acts in an ___________ direction of movement.

• similar
• opposite
• parallel

Multiple Choice

Real Work Examples: select example of friction that is harmful.

• pencil marking on paper

• engine parts wearing out

• sand placed on ice in the winter
• uUsing an eraser to erase marks