Forces and Motion

One way that a force can cause the change in an object's motion is to...

• do nothing.
• eat ice cream.
• start the object moving.
• shine on the object.

_____ is the force that slows and stops motion between touching objects.

• Friction
• Gravity
• Pull
• Push

Which has the least friction?

• snowboard on a snowy hill
• running on the playground
• sandpaper on wood
• a racer on a track

Why is there less friction between two ice cubes touching than between sandpaper on wood?

• They have rough surfaces.
• They have loud surfaces.
• They have smooth surfaces.
• They have bright surfaces.

What is one way to reduce friction?

• Put sandpaper between the surfaces that touch.
• Push the surfaces closer together.
• Shine a light on the surfaces.
• Put a slippery substance between the surfaces.

How does friction help us move from place to place?

• Friction does not help us.
• Friction keeps us from slipping and sliding.
• Friction only helps cats.
• Friction makes us slip and fall.

In which of the following activity is friction useful?

• sliding down a snowy hill on a sled
• ice skating
• running around a track
• roller blading

In the image, what force is acting on arrow A?

• friction
• gravity
• push
• Jedi force

What keeps the Moon in orbit around Earth?

• Earth's rotation.
• Earth's atmosphere.
• Earth's gravity.
• Earth's shape.

Which would require the most force to move?

• a toy car
• a sleeping cat
• a science book
• a chair with a friend sitting in it