If block A is moving with an acceleration of `5ms^(-2)`, the acceleration of B w.r.t. ground is

Options

A. `5ms^(-2)`
B. `5sqrt(2)ms^(-2)`
C. `5sqrt(5)ms^(-2)`
D. `10ms^(-2)`

Answer

C

Explanation

By virtual word method:
Acceleration of B w.r.t. A will be `10 ms^(-2)` downward.
Apart from this, B also has an acceleration `5 ms^(-2)` in horizontal direction along with A, so net acceleration of B is
`sqrt(10^(2)+5^(2))= sqrt(100+25)=sqrt(125) = 5sqrt(5) ms^(-2)`.