Question

A block of mass M rests on a horizontal surface. The coefficients of static and kinetic friction are 0.5 and 0.4. A horizontal force is applied on the block, which is just sufficient to start the block moving. If the same force is maintained to start the block begins the acceleration of the block will be

Answer 1

Answer:

Here , maximum value of static friction that can act on the body = μ

s

mg

= 25 N

(i) Since the applied force is less than the maximum possible value of static friction

therefore , the force of friction will be just enough to stop the motion of the body.

Here , friction force = 15 N

(ii) Here, applied force = maximum possible value of static friction.

Friction force = 25 N

(iii) Here , applied force > maximum value of static friction.

Therefore , the body moves and kinetic friction acts on the body.

Friction force = μ

k

mg = 20 N.