Unit Review - Forces Grade 3

Which of the following does not describe the action of forces?

• kicking a ball

• lifting a box

• boiling water

• a bird flying

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-5

Which of the following statements about forces are correct?

A         A force is needed to move objects.

B         A force is a push or a pull on an object.

C         Only one force can act on an object at a time.

D         Nothing starts to move until it is pushed or pulled.

• A and C only

• B and D only

• A, B and C only

• A, B and D only

Answer explanation

A force is needed to move objects, and nothing starts to move until it is pushed or pulled. A force is a push or a pull on an object. More than one force can act on an object at a time.

Tags

NGSS.MS-PS2-2

When a tennis player hits the ball to the other side of the court, he changes the ball’s ________.

• size

• shape

• color

• direction

Answer explanation

Hitting the tennis ball to the other side of the court changes the direction in which the ball is moving.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-1

Which action is wrongly matched to the force?

• A

• B

• C

• D

Answer explanation

Lifting a bag involves a pull.

Tags

NGSS.3-PS2-1

Two workers are moving a big box.

If the forces acting on the box are balanced, the box will ________.

• move to the left

• move to the right

• remain stationary

• move to the left with increasing speed

Answer explanation

When the forces acting on the box are balanced, the box will remain stationary.

Tags

NGSS.MS-PS2-2

Alex and Ben are trying to move a heavy box. It will be easier to move the box if ________.

• Alex pullsthe box alone

• Alex and Ben push the box in opposite directions

• Alex pulls the box and Ben pushes the box from the other side

• Alex pullsthe box and Ben pushes the box on the same side

Answer explanation

It will be easier to move the box if Alex and Ben work together to exert a bigger force on the box in the same direction. When Alex pulls the box and Ben pushes the box from the other side, they are exerting forces that act in the same direction.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-1

Which of the following shows unbalanced forces acting on an object?

• A rising balloon

• A person sitting on a chair

• A stationary boat on a lake

• A car parked at a parking lot

Answer explanation

The balloon is moving upwards.

This indicates that the downward force is less than the upward force.

The forces are unbalanced.

Tags

NGSS.MS-PS2-2

Which action is wrongly matched to the effect of the force?

• A

• B

• C

• D

Answer explanation

When the force is exerted in the same direction that the ping pong ball is moving, the ball speeds up.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-1

Which of the following about the effect of forces on an object is incorrect?

• A force cannot change the size of an object

• A force can cause an object to stop moving

• A force can change the speed of a moving object

• A force can change the direction in which an object is moving

Answer explanation

A force can change the size, shape and movement of an object.

Tags

NGSS.MS-PS2-2

Which of the following requires a pull force?

• Throwing a ball

• Opening a drawer

• Typing on a keyboard

Answer explanation

A pull force results in a motion towards the source of the force.

When you open a drawer, you are moving the drawer towards your body.