A block `A` with mass 100kg is resting on another block `B` of mass 200kg. As shown in figure a horizontal rope tied to a wall hold it. The coefficient of friction between `A` and `B` is `0.2` while coefficient of friction between `B` and the ground is `0.3` . the minimum required force `F` to start moving `B` will be.

Answer

110

Explanation

`F = f_(AB) + f_(BG)`
`= mu_(AB) m_(C ) g + mu_(BD) (m_(A) + m_(B)) g`
`= 0.02 xx 100 xx 10 + 0.03 (300) xx 10`
= 20 + 90 = 110 N