Question

Consider the situation as shown in the diagram.
The coefficient of friction between the block is `0.5`. The acceleration of the lower block is
A. `1 m//s^(2)`
B. `1.5 m//s^(2)`
C. `2 m//s^(2)`
D. `2.5 m//s^(2)`

Answer 1

Correct Answer - A
`f_(max) = mu N = 0.5 xx 20 = 10 N`
Since `7 N gt 10 N` , the upper block will not move with respect to the lower block.
Both the blocks will move ove together with acceleration
`7 = ( 2 + 5)a rArr a = 1 m//s^(2)`