Grade VIII Physics ''Friction''

Front

What happens when we rub our hands together?

Back

Frictional force works between them, energy is released, our hands become warm, all of the above.

Front

In which direction does the force of friction act when a boy pushes a box from right to left?

Back

From left to right.

Front

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

Back

The marble would remain at a constant speed.

Front

What direction does friction act relative to a moving object?

Back

Opposite.

Front

In which sport is the least amount of friction required?

Back

Ice skating.

Front

Define friction.

Back

Friction is a force that opposes the relative motion of two surfaces in contact.

Front

What are the two main types of friction?

Back

Static friction and kinetic (or dynamic) friction.

Front

What is static friction?

Back

Static friction is the frictional force that prevents two surfaces from sliding past each other.

Front

What is kinetic friction?

Back

Kinetic friction is the frictional force that acts between moving surfaces.

Front

How does surface texture affect friction?

Back

Rough surfaces generally produce more friction than smooth surfaces.