Question

When the applied force is doubled, then friction becomes:

• A. doubled
• B. halved
• C. can't say
• D. zero

Answer 1

Answer: (C)

If the body is not moving , then static frictional force comes into play .Static friction is a self adjusting force , hence when the applied force is doubled ,then friction becomes double .

But when the object is moving, then kinetic friction comes into play. And when applied force is greater than the frictional force, then friction willn't change according to the applied force.

So we can't say directly that the friction force will get doubled or halved on doubling the force.