Question

A block of mass $5Kg$ is placed over a block of mass $10Kg$,as shown in Fig. The coefficient of friction between the two block is $\mu$=0.5. An external force of $80N$ is exerted on a $10Kg$ block. Find the acceleration of both the blocks.

Answer 1

Check whether it will move with common acceleration or not.

Ref. image

$a=\frac{80}{15}=\frac{16}{3}m{s}^2$

Maximum possible acceleration of $5kg$ block

$a_1=\frac{FrictionForce}{Mass}$

$a_1=\frac{25}{5}=5m{s}^2$

As this acceleration is less than the common acceleration, so both will move with same acceleration.

$a=\frac{16}{3}m{s}^2$