A spring-mass system vibrates such that mass travel on surface of coefficient of friction $\mu$. Mass is released after compressing the spring by distance a and it travels upto distance $b$ after its equilibrium position, then travelling from $x = -a$ to $x = b$ the reduction in its amplitude will be :-
$\frac{\mu mg}{K}$
$\frac{2 \mu mg}{K}$
$\frac{\mu g}{K}$
$\frac{k}{\mu mg}$
A bullet of mass $20 \,g$ leaves a riffle at an initial speed $100 \,m / s$ and strikes a target at the same level with speed $50 \,m / s$. The amount of work done by the resistance of air will be ......... $J$
A body dropped from height $‘H’$ reaches the ground with a speed of $1.1 \sqrt {gH}$ . Calculate the work done by air friction? .............. $\mathrm{mgH}$
By what reasons chemical energy produced in chemical process ?
A ball is released from certain height. It loses $50\%$ of its kinetic energy on striking the ground. It will attain a height again equal to
A particle of mass $500 \,gm$ is moving in a straight line with velocity $v=b x^{5 / 2}$. The work done by the net force during its displacement from $x=0$ to $x =4 \,m$ is ...................$J$ (Take $b =0.25 \,m ^{-3 / 2} s ^{-1}$ )