Two blocks each of mass M are resting on a frictionless inclined plane as shown in fig then:

Options

A. the block A moves down the plane
B. the block B moves down the plane
C. both the blocks remain at rest
D. both the blocks move down the plane

Answer

A

Explanation

The force acting down the plane for blocks A and B are:
`F_(A)=Mg sin 60^(@)=sqrt(3)/2 Mg=0.866Mg`
`F_(B)=Mgsin 30^(@)=1/2Mg=0.5 Mg`
Since `F_(A) gt F_(B)` the block A moves down the plane.