Assertion: The acceleration of a body down a rough inclined plane is grater than the acceleration due to gravity.
Reason: The body is able to slide on an inclined plane only when its acceleration is greater than acceleration due to gravity.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both aseertion and reason are false.

Answer

D

Explanation

Let a body which has mass `m` is placed on an inclined plane whose inclination is greater than angle of repose. The force on the body down the inclined plane is given by
`F= mg sin theta- mu R`
`ma= mg sin theta-mu mg cos theta`
or `a= g sin theta-mu g sin theta`
`= g(sin theta-mu cos theta)`....(i)
It is obvious from Eq. (i) that
`altg`