Question

Assertion (A): Block of mass m is kept at rest on an inclined plane, the rest force applied by the surface to the block will be mg.
Reason (R) Normal contact force is the resultant of normal contact force and friction force.
​

Answer 1

Answer is mg

Explanation

Total force exerted by block =mg, thus inclined plane also exerts the same force back. This can be seen as follows:

Normal Force due to inclined plane on block =mgcosθ

Friction force =mgsinθ

Thus total force =mg Root cos2 θ + sin2 θ

 (because normal and friction forces are perpendicular to each other.

Answer 2

Answer:

Correct option is

A

mg

Total force exerted by block =mg, thus inclined plane also exerts the same force back. This can be seen as follows:

Normal Force due to inclined plane on block =mgcosθ

Friction force =mgsinθ

Thus total force =mg

cos

2

θ+sin

2

θ

(because normal and friction forces are perpendicular to each other.