Two masses of 10 kg and 20 kg respectively are tied together by a massless spring. A force of 200 N is applied on a 20 kg mass as shown in figure. At the instant shown, the acceleration of 10 kg mass is 12 `m s^(-2)` the acceleration of 20 kg mass is

Options

A. 0
B. `10 ms^(-2)`
C. `4 ms^(-2)`
D. `12 ms^(-2)`

Answer

C

Explanation

Force on 10 kg block` = ma10 xx 12 = 120 N`.
The total force applied = 200 N.
The force acting on 20 kg block = 200-120 = 80 N.
The acceleration of this block`=(80)/(20)= 4 ms^(-2)`