Two masses `A` and `B` of `10 kg` and `5 kg`, respectively , are connected with a string passing over a frictionless pulley fixed at the corner of a table as shown. The coefficient of static friction between `A` and the table is `0.2`. The minimum mass `C` that should be placed on `A` to prevent it from moving is equal to

Options

A. `12 kg`
B. `5 kg`
C. `10 kg`
D. `15 kg`

Answer

D

Explanation

`m` : mass of block `C`.
For no motion
`(mu(10 + m) ge 5g`
`0.2 (10 + m)ge 5`
`m ge 15 kg`
`m_(min) = 15 kg`