friction

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

• similar
• opposite
• parallel
• west

How does friction affect speed?

• more friction decreases speed
• more friction increases speed
• less friction decreases speed

The rougher the surface, the faster an object will travel over the surface.

• True
• False

When most objects with smooth surfaces rub, there is less friction.

• True
• False

How would the absence of friction affect a marble traveling on a long, straight path?

• The marble’s speed would decrease.
• The marble’s speed would increase.
• The marble would stop immediately. 
• The marble would remain at constant speed.

When two surfaces rub, the irregularities of one surface get caught on those of the other surface?

• True
• False

Rougher surfaces have ...

• greater friction
• less friction
• the same level of friction

What does friction produce?

• light
• sound
• heat
• gravity

Which of the following answers is the most scientific answer for the question:

What is friction?

• The random force between two solids, liquids, or gases.

• The contact force between two solids, liquids, or gases that slide past one another.

• The thing that creates static electricity

• A force that is random

When there is friction, the energy of an object's motion is converted into _______ energy

• heat

• kinetic

• stronger

• friction