A 2 kg block is placed over a 4 kg block and both are placed on a smooth horizontal surface. The coefficient of friction between the blocks is 0.20. Find the acceleration of the two blocks if a horizontal force of 12 N is applied to (a). the upper block, (b). the lower block. Take g=10 m/`s^2`.

Options

A. `2ms^(-2), 2ms^(-2)`
B. `2ms^(-2), 1ms^(-2)`
C. `3ms^(-2), 1ms^(-2)`
D. `4ms^(-2), 1ms^(-2)`

Answer

A

Explanation

`F` is greater than `mu_(s)` mg The blocks move with different acceleration
`a_(u) =mu_(k) g, a_(L) = ((F -mu_(k)m_(u)g))/(m_(L))` .