A ball is projected at $60^o$ from horizontal at $200\, m/s$. At maximum height during its flight it explodes into $3$ equal fragments. Out of them one part travel at $100\, m/s$ vertically up while other at $100\, m/s$ vertically down, then third part will have speed just after explosion :-
$100\, m/s$ horizontal
$300\, m/s$ horizontal
$300\, m/s\, 60^o$ to horizontal
$200\, m/s\, 60^o$ to horizontal
A wagon weighing $1000\, kg$ is moving with a velocity $50\,km/h$ on smooth horizontal rails. A mass of $250 \,kg$ is dropped into it. The velocity with which it moves now is ......... $km/hour$
A $^{238}U$ nucleus decays by emitting an $\alpha$ particle of speed $v\,m{s^{ - 1}}$. The recoil velocity of the residual nucleus is (in $m{s^{ - 1}}$)
Two skaters $A$ and $B$ of weights in the ratio $5 : 7$ start facing each other $6\,metres$ apart on a horizontal smooth surface. They pull on a rope stretched between them. How far has each moved when they meet?
A man (mass $= 50\, kg$) and his son (mass $= 20\, kg$) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of $0.70\, ms^{-1}$ with respect to the man. The speed of the man with respect to the surface is ........ $ms^{-1}$
A bullet of mass $40 \,g$ is fired from a gun of mass $10 \,kg$. If velocity of bullet is $400 \,m / s$, then the recoil velocity of the gun will be ..........