In Figure, a body A of mass m slides on plane inclined at angle to the horizontal and is the coefficient of friction between A and the plane. A is connected by a light string passing over a frictionless pulley to another body B, also of mass m, sliding on a frictionless plane inclined at angle to the horizontal. Which of the following statements are true?
(a) A will never move up the plane.
(b) A will just start moving up the plane when
(c) For A to move up the plane, must always be greater than .
(d) B will always slide down with constant speed.
The correct answer is the option:
(b) A will just start moving up the plane when
(c) For A to move up the plane, must always be greater than .
Explanation:
In the fig. below,= coefficient of friction of A whereas B is on a frictionless surface.
(i) when A is about to start
When A just start moving upward
If on the plane, the body A moves upward, and B moves downward
Hence, opt (c) is verified and opt (a) is rejected.
(ii) If the body B moves upward and A moves downward then,
Since and are acute angles, > , thus, may be true
Since it is now clear that body B can also move upward, opt (d) is also rejected.