Inside a horizontally moving box, an experimenter finds that when an object is placed on a smooth horizontal table and is released, it moves with an acceleration of $10\,m / s ^2$. In this box if $1\,kg$ body is suspended with a light string, the tension in the string in equilibrium position (w.r.t. experimenter) will be$.........\,N$ (Take $g =10\,m / s ^2$ )
A parachutist with total weight $75 \,kg$ drops vertically onto a sandy ground with a speed of $2 \,ms ^{-1}$ and comes to halt over a distance of $0.25 \,m$. The average force from the ground on her is close to ............ $N$
Two masses $M$ and $m$ are connected by a weightless string. They are pulled by a force $F$ on a frictionless horizontal surface., the acceleration of mass $m$ is