$A$ horizontal force of $129.4 \, N$ is applied on a $10 \, kg$ block which rests on a horizontal surface. If the coefficient of friction is $0.3$,the acceleration should be ....... $m/s^2$.

With what minimum velocity should a block be projected from the left end $A$ towards end $B$ such that it reaches the other end $B$ of a conveyor belt moving with a constant velocity $v$ towards the left? The length of the belt is $L$ and the coefficient of friction between the block and the belt is $\mu$.

$A$ block of mass $50\, kg$ slides over a horizontal distance of $1\, m$. If the coefficient of friction between their surfaces is $0.2$,then the work done against friction is ......... $J$.

$A$ small body of mass $500 \,g$ moves on a rough horizontal surface before finally stopping. The initial velocity of the body is $2 \,m/s$ and the coefficient of friction is $0.3$. Find the absolute value of the average power developed by the frictional force during the time of motion. (Take $g = 10 \,m/s^2$) (in $\,W$)

$A$ horizontal force of $4\,N$ is needed to keep a block of mass $0.5\,kg$ sliding on a horizontal surface with a constant speed. The coefficient of sliding friction must be: $[g = 10\,m/s^2]$

$A$ body of mass $20 \,kg$ is moving on a rough horizontal plane. $A$ block of mass $3 \,kg$ is connected to the $20 \,kg$ mass by a string of negligible mass through a smooth pulley as shown in the figure. The tension in the string is $27 \,N$. The coefficient of kinetic friction between the heavier mass and the surface is $\left(g=10 \,m/s^2\right)$.