Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : Body $'P'$ having mass $M$ moving with speed $'u'$ has head-on collision elastically with another body $'Q'$ having mass $'m'$ initially at rest. If $m< < M,$ body $'Q'$ will have a maximum speed equal to $'2u'$ after collision.
Reason $R$ : During elastic collision, the momentum and kinetic energy are both conserved.
In the light of the above statements, choose the most appropriate answer from the options given below:
$A$ is not correct but $R$ is correct.
Both $A$ and $R$ are correct but $R$ is $NOT$ the correct explanation of $A$.
Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$.
$A$ is correct but $R$ is not correct.
Two identical spheres move in opposite directions with speeds $v_1$ and $v_2$ and pass behind an opaque screen, where they may either cross without touching (Event $1$) or make an elastic head-on collision (Event $2$)
Two pendulums with identical bobs and lengths are suspended from a common support such that in rest position the two bobs are in contact (figure). One of the bobs is released after being displaced by $10^o$ so that it collides elastically head-on with the other bob.
$(a)$ Describe the motion of two bobs.
$(b)$ Draw a graph showing variation in energy of either pendulum with time, for $0\, \leqslant \,t\, \leqslant \,2T$, where $T$ is the period of each pendulum.
A truck moving on horizontal road towards east with velocity $20\, ms^{-1}$ collides elastically with a light ball moving with velocity $25\, ms^{-1}$ along west. The velocity of the ball just after collision
A body falling on the ground from $a$ height of $10\, m$, rebounds to a height $2.5\, m,$ then the ratio of the velocities of the body just before and after the collision will be
A mass $'m'$ moves with a velocity $'v'$ and collides inelastically with another identical mass in rest. After collision the $I^{st}$ mass moves with velocity $\frac{v}{{\sqrt 3 }}$ in a direction perpendicular to the initial direction of motion. Find the speed of the $2^{nd}$ mass after collision