Which of the following statements is correct ?
Kinetic energy of a system can be changed without changing its momentum
Kinetic energy of a system cannot be changed without changing its momentum.
Momentum of a system cannot be changed without changing its kinetic energy
Body cannot have energy without having momentum.
The energy required to break one bond in $DNA$ is $10^{-20}\, J.$ This value in $eV$ is nearly
If the kinetic energy of a body is directly proportional to time $t,$ the magnitude of force acting on the body is
$(i)$ directly proportional to $\sqrt t$
$(ii)$ inversely proportional to $\sqrt t$
$(iii)$ directly proportional to the speed of the body
$(iv)$ inversely proportional to the speed of body
A projectile is fired with $KE$ of $1\,kJ$. If the range is maximum, .......... $J$ is its $KE$ at the highest point.
Two bodies with kinetic energies in the ratio of $4 : 1$ are moving with equal linear momentum. The ratio of their masses is
Two identical uniform discs roll without slipping on two different surfaces $AB$ and $CD$ (see figure) starting at $A$ and $C$ with linear speeds $v _1$ and $v _2$, respectively, and always remain in contact with the surfaces. If they reach $B$ and $D$ with the same linear speed and $v_1=3 \ m / s$, then $v_2$ in $m / s$ is $\left(g=10 \ m / s ^2\right)$