Question

In the figure shown, a block of weight 10 N resting on a horizontal surface. The coefficient of static friction between the block and the surface $\mu _ { s } = 0.4$ . A force of 3.5 N will keep the block in uniform motion, once it has been set in motion. A horizontal force of 3 N is applied to the block, then the block will

• A. Move over the surface with constant velocity
• B. Move having accelerated motion over the surface
• C. Not move
• D. First it will move with a constant velocity for some time and then will have accelerated motion

Answer 1

Answer: (C)

Not move

Answer 2

$F _ { l } = \mu _ { s } R = 0.4 \times m g = 0.4 \times 10 = 4 N$ i.e. minimum 4N force is required to start the motion of a body. But applied force is only 3N. So the block will not move.