Question

In the given figure a block of weight $10N$ is resting on a horizontal surface. The coefficient of static friction between the block and the surface is ${\mu }_s=0.4$. A force of $3.5N$ will keep the block in uniform motion, once it has been set in motion. A horizontal force of $3N$ 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. will not move.
• D. first it will move with a constant velocity for some time and then it will have an accelerated motion.

Answer 1

The correct option is C will not move.

$f_s^{max}=\mu N=0.4\times 10N=4N$
The applied force is less than max $f_s^{max}$, so the block would not move.