Work, Energy, Friction, and Efficiency

work is done when

• the object you apply a force on moves

• any force is applied to an object, regardless if it moves or not

• the force is zero

• the force and direction of motion are perpendicular

The ability to do work is called

• energy

• force

• power

• machine

What is the unit of report for energy?

• Joules

• meters

• newtons

• grams

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

If the net work done on an object is positive, what can you conclude about the object's motion?

• The object is speeding up.

• The object is moving with a constant velocity.

• The object is slowing down.

• The object is at rest; its position is constant.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

You pick up a 3.8 kg can of paint from the ground and lift it to a height of 1.4 m. You hold the can stationary for half a minute, waiting for a friend on a ladder to take it. How much work do you do during this time (when the can of paint was stationary)?

• 52 J

• 30 J

• 0 J

• 25 J

A man pushes a boulder and the boulder does not move. Which statement correctly describes the scenario

• work is being done by a single object

• All work done is external to the system

• by pushing on the rock, the man causes a transfer of energy

• no work is being done on the object

Which two measurements must be parallel for work to be done

• force and displacement

• distance and direction

• constant force and power

• power and work

A man carries a box across a room at constant velocity. Is work being done on the box by the man?

• Yes

• No

• Half of the time

• Not enough information

Tags

NGSS.HS-PS3-2

A man lifts a box into the air. Is work being done by gravity when the box is lifted into the air?

• Yes

• No

• Half of the time

• Not enough information

Tags

NGSS.HS-PS2-4

if you push a cart with a force of 60 N resulting in 120 J of work.. how far did you move the cart? 

• 7200 m
• 0 m
• 2 N 
• 2 m

Tags

NGSS.MS-PS3-5