Question

| 4.
A block A of mass 2 kg is placed over a plank B of
mass 4 kg. Plank B is placed over a smooth
horizontal surface. The coefficient of friction between
A and Bis 0.4. Block Ais given a velocity v, towards
right. Find the magnitude of acceleration of Brelative
to A.​

Answer 1

Answer:

The acceleration of the B is 1.96 m/s²

Explanation:

When the Block A is moved, the friction force will act on it by Newton's third law an opposite force will act on plank B which will provide the acceleration to plank B

The friction force acting on block B

$F=\mu N$

$F=0.4\times 2g$

$\implies F=0.4\times 2\times 9.8$ N

or F = 7.84 N

An opposite force of this magnitude will act on the plank which will provide the acceleration to the plank

Therefore the acceleration due to this force = F/mass of the plank

                                                                         = 7.84/4

                                                                        = 1.96 m/s²

Answer 2

Explanation:

A block A of mass m is placed over a plank B of mass 2 m. Plank B is placed over a smooth horizontal surface. The coefficient of friction between A and B is Block A is given a velocity v0 towards right. Then