Question

A block A kept on an inclined surface just begins to slide if the inclination is 30°. The block is replaced by another block B and it is found that it just begins to slide if the inclination is 40°.
(a) mass of A > mass of B
(b) mass of A < mass of B
(c) mass of A = mass of B
(d) all the three are possible

Answer 1

Answer:

(B) mass of A<B

Explanation:

it is because the force which make it slide downward is mgsin(thieta) when we break the forces . so the as the mass increases the angle has to be increased in order to make the block slide down through the inclined plane.

So mass A has to be less than the mass B

Answer 2

Mass of A > mass of B. We know that gravitational force g=m*a where mass stands for mass and a stands for acceleration and gravitational force increases with height from the ground.

Explanation:

• At an angle of 30°, the frictional force of block A is smaller than gravitational force hence slides down. But as mass of block B is greater than block A, the frictional force exerted by the block on the inclined surface becomes greater than the gravitational force that pulled down the block A.
• Hence, the inclination of the surface at 40° increases the height of the block B from ground, increasing the gravitational force greater than the frictional force.
• Thus, the block B slides down. This reveals that an object with greater mass requires greater inclination to slide down.