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. 15 kg
B. 10 kg
C. 5 kg
D. 20 kg

Answer

A

Explanation

(a) ` mu (m_(A)+m_(C))g=m_(B)g`
`therefore" " m_(C)=(m_(B))/(mu)=m_(A)=(5)/(0.2)-10=15 kg`