You are holding a vertical cylindrical rod of mass $1 \, kg$ by pressing it (with a force of $12 \, N$) with two fingers. The coefficient of friction between the rod and the fingers is $\mu = 0.5$. The force of friction on the rod will be ........ $N$.

$A$ body of mass $2 \, kg$ moving on a horizontal surface with an initial velocity of $4 \, m/s$ comes to rest after $2 \, s$. If one wants to keep this body moving on the same surface with a constant velocity of $4 \, m/s$,the force required is ........ $N$.

Which of the following is correct when a person walks on a rough surface?

$A$ body of weight $64 \ N$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are $0.8$ and $0.6$ respectively,then the acceleration of the body will be

$A$ body of weight $64 \,N$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are $0.6$ and $0.4$ respectively, the acceleration of the body is (Acceleration due to gravity $= g$)

$A$ $300 \ kg$ crate is dropped vertically onto a conveyor belt that is moving at $1.20 \ m/s$. $A$ motor maintains the belt's constant speed. The belt initially slides under the crate,with a coefficient of friction of $0.400$. After a short time,the crate is moving at the speed of the belt. During the period in which the crate is being accelerated,find the work done by the motor which drives the belt.