Both the blocks as shown in figure are given together a horizontal velocity towards right. The acceleration of the centre of mass of the system of block is `(m_(A) = 2m_(B) = 2kg)`.

Options

A. zero
B. `(5)/(3)m//s^(2)`
C. `(7)/(3)m//s^(2)`
D. `2 m//s^(2)`

Answer

D

Explanation

Net external foce on the two blocks (whether they move with same retardation or not)
`f_(ext) = (0.2) (2 + 1) xx 10 = 6N`
`:. a_(cm) = (f_(ext))/(2 + 1) = 2 m//s^(2)`