Question

Frictional force always opposes:

• A. The state of rest
• B. The state of motion
• C. None of the above
• D. Both the states

Answer 1

Answer: (B)

Both the states

A frictional force always opposes the relative motion among the surfaces.

friction force can be classified as static friction and kinetic friction,

in brief,

static friction acts when an external force acts on the body and body tends to move(still at rest as external force yet to overcome limiting friction(maximum value of static), therefore static friction starts acting in opposition.

kinetic friction acts when an external force acts on the body to provide acceleration and it overcomes the limiting friction, therefore kinetic starts acting in opposition.