Which of the following statements is true
In elastic collisions, the momentum is conserved but not in inelastic collisions
Both kinetic energy and momentum are conserved in elastic as well as inelastic collisions
Total kinetic energy is not conserved but momentum is conserved in inelastic collisions
Total kinetic energy is conserved in elastic collisions but momentum is not conserved in elastic collisions
Find work done by friction if block reaches to the end with constant velocity
In $a$ smooth stationary cart of length $d, a$ small block is projected along it's length with velocity $v$ towards front. Coefficient of restitution for each collision is $e$. The cart rests on $a$ smooth ground and can move freely. The time taken by block to come to rest $w.r.t$. cart is
A block of mass $m$ is moving with a velocity $u$ on a smooth horizontal surface towards a wedge of same mass initially kept at rest. Wedge is free to move in any direction. Initially the block moves up the smooth incline plane of the wedge to a height $h$ and again moves down back to the horizontal plane. In this process the wedge gains a velocity equal to
A big ball of mass $M$, moving with velocity $u$ strikes a small ball of mass $m$, which is at rest. Finally small ball obtains velocity $u$ and big ball $v$. Then what is the value of $v$
An unknown nucleus collides with a ${}^4He$ nucleus, and after the collision the two nuclei travel in perpendicular directions relative to each other. If kinetic energy is lost in the collision, the unknown nucleus must be