A block `A` of mass `10 kg` rests on a second block `B` of mass `8 kg`. The coefficients of friction at various surfaces are shown in figure. A horizontal force of `100 N` is applied on upper block at `t=0`. Determine the velocity of block `A` relative to block `B` after `0.01 s` of application of force. The system is initially at rest. Express your answer in `cm//s`. Take `g=10 m//s^(2)`.

Answer

1

Explanation

The free body diagram of two blocks is as shown in figure


For `A rarr 100-50 = 10 a_(1) rArr a_(1) = 5m//s^(2)`
For `B rarr 50 -18 = 8a_(2) rArr a_(2) = 4 m//s^(2)`
Acceleration of `A` relative to `B, a_("rel") = 1 m//s^(2)`
`V_("vel") = 0+a_("rel") x t = 1 xx 0.01 m//s = 1 cm//s`