Question

A body of mass 400 g slides on a rough horizontal surface. If the frictional force is 3 N, then the magnitude of contact force is (take g=10ms?) [ ] a) 4N b) 3 N c) 7 N d) 5 N​

Answer 1

Answer:

Option (d). The magnitude of contact force is 5 N.

Explanation:

The mass of the body, m = 400 g = 0.4 Kg

The frictional force acting on the body, f = 3 N

The body is sliding over a horizontal surface. So there will be a normal reaction force acting on the body perpendicular to the horizontal surface.

Normal reaction, N = mg

                                = 0.4 × 10 = 4 N

The magnitude of contact force can be calculated using the equation,

  F = √(N² + f²)

     = √(4² + 3²)

     = √25

∴ F = 5 N