Question

A block of mass 5 kg and surface area $2m^2$ just begins to slide down an indtried Plane when the angle of inclination is ${30}^{\circ }$ . Keeping mass same, the surface area of the block is doubled. The angle at which this starts sliding down is

• A. ${30}^{\circ }$
• B. ${60}^{\circ }$
• C. ${15}^{\circ }$
• D. None

Answer 1

The correct option is A ${30}^{\circ }$

The friction acting on a body is independent of the surface area of contact. It depends only on the coefficient of friction and the normal force acting on the object.
Therefore, the angle at which the block starts sliding down will not change even though the surface area of the block is doubled.