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 ............ $N$
$600$
$1200$
$1350$
$1950$
A smooth cylinder of mass $m$ and radius $R$ is resting on two corner edges $A$ and $B$ as shown in fig. The relation between normal reaction at the edges $A$ and $B$ is
A rope of length $10\, m$ and linear density $0.5\, kg/m$ is lying lengthwise on a smooth horizontal floor. It is pulled by a force of $25\, N$. The tension in the rope at a point $8\, m$ away from the point of application is ....... $N$
A chain lying on an absolutely smooth table, half of it hanging over the edge of the table as shown in figure $(a)$. The time it takes to slip off the table is affected if two equal weights be attached, one to each end as shown in figure $(b)$ .
$t_a$ : time taken to slip in situation $'a'$
$t_b$ : time taken to slip in situation $'b'$
The horizontal acceleration that should be given to a smooth inclined plane of angle $sin^{-1}\, (1/l)$ to keep an object stationary on the plane relative to the inclined plane is
Two masses $M$ and $m$ are connected by a weightless string. They are pulled by a force $F$ on a frictionless horizontal surface. The tension in the string will be