A body of mass $m$ starts from rest with a constant power. If velocity of the body at displacement $s$ is $v,$ then the correct alternative is

A body of mass $m$ was slowly pulled up the hill by a force $F$ which at each point was directed along the tangent of the trajectory. All surfaces are smooth. Find the work done by this force

A particle is placed on the top of a hemispherical shell of same mass. Shell is free to move on the smooth ground. If particle is given a gentle push and reaches to angular position $q$ as shown in figure then for an observer fixed on a shell, ratio of reaction force exerted by shell to pseudo force (as observed from shell) acting on particle, is

Consider the system shown in the figure. Coefficient of friction between the block and table is $\mu =0.5.$ The system is released from rest. Find the work done by friction, when the speed of block is $10 {\mathrm{ms}}^{-1}(m=1 \mathrm{kg})$

Find the maximum compression in the spring, if the lower block is shifted to rightwards with acceleration $a$. All the surfaces are smooth.