The coefficient of static friction between a wooden block of mass $0.5\, kg$ and a vertical rough wall is $0.2$ The magnitude of horizontal force that should be applied on the block to keep it adhere to the wall will be $N$ $\left[ g =10\, ms ^{-2}\right]$
$25$
$30$
$30$
$20$
A car is moving with uniform velocity on a rough horizontal road. Therefore, according to Newton's first law of motion
A block of mass $m$ (initially at rest) is sliding up (in vertical direction) against a rough vertical wall with the help of a force $F$ whose magnitude is constant but direction is changing. $\theta = {\theta _0}t$ where $t$ is time in sec. At $t$ = $0$ , the force is in vertical upward direction and then as time passes its direction is getting along normal, i.e., $\theta = \frac{\pi }{2}$ .The value of $F$ so that the block comes to rest when $\theta = \frac{\pi }{2}$ , is
A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is :
When two surfaces are coated with a lubricant, then they
In the figure, a block of weight $60\, N$ is placed on a rough surface. The coefficient of friction between the block and the surfaces is $0.5$. ........ $N$ should be the maximum weight $W$ such that the block does not slip on the surface .