Friction

When we brake a bike, what force is created?

• Frictional

• Magnetic

• Gravitational

• Spring

Friction happens when two things touch or rub against each other.

• True

• False

What energy does friction often create (e.g. when we rub our hands together)?

• electrical

• sound

• light

• heat

Long ago, humans used friction to create fire.

• True

• False

Under magnification, even smooth surfaces appear rough.

• True

• False

What do football boots have to grip the surface well?

• Long laces

• Metal studs

• Leather uppers

• Cushioned soles

Rock climbers use chalk to increase their grip.

• True

• False

Friction on ice is high.

• True

• False

Skiers wax their skis to reduce friction.

• True

• False

What frictional force did the Egyptians use to build the pyramids?

• Static

• Sliding

• Rolling

• Fluid