A particle moves under the effect of a force $F = cx$ from $x = 0$ to $x = x_1$. The work done in the process is
$cx_1^2$
$\frac{1}{2}cx_1^2$
$cx_1^3$
zero
Work done in time $t $ on a body of mass $m$ which is accelerated from rest to a speed $v$ in time ${t_1}$ as a function of time $t$ is given by
Force acting on a particle moving in a straight line varies with the velocity of the particle as $F = \frac{K}{\upsilon }$ where $K$ is a constant. The work done by this force in time $t$ is
If a spring extends by $x$ on loading then energy stored by the spring is ($T$ is tension in spring, $K$ is spring constant)
When a ball is freely fallen from a given height it bounces to $80\%$ of its original height. What fraction of its mechanical energy is lost in each bounce ?
A body of mass $1\, kg$ is thrown upwards with a velocity $20\, m/s$. It momentarily comes to rest after attaining a height of $18\, m$. How much energy is lost due to air friction ............. $\mathrm{J}$ $(g = 10\, m/s^2)$