A boy throws a ball of mass 0.5 kg with a velocity of 10 m/s to the east. What is the momentum of the ball?

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and spring reads 49 N, when the lift is stationary. If the lift moves downward with an acceleration of $\;5{\rm{\;m}}{{\rm{s}}^{ - 2}}$ , the reading of the spring balance will be

A hockey player is skating northward and suddenly turns westward with the same speed to avoid a collision. The force that acted on the player while turning is:

A block of mass 5 kg, resting on a horizontal surface, is connected by a cord, passing over a light frictionless pulley to a hanging block of mass 5 kg. The coefficient of kinetic friction between the block and the surface is 0.5. Tension in the cord is [Take ${\rm{g}} = 9.8{\rm{\;m}}{{\rm{s}}^{ - 2}}$]

Two putty balls of equal mass moving with equal velocity in mutually perpendicular directions, stick together after collision. If the balls were initially moving with a velocity of $45\sqrt 2 \,m{s^{ - 1}}$ each, the velocity of their combined mass after collision is

If in a stationary lift, a man is standing with a bucket full of water, having a hole at its bottom. The rate of flow of water through this hole is ${R_0}$. If the lift starts to move up and down with same acceleration and then that rates of flow of water are ${R_u}\,and\,{R_d}$, then

A shell of mass 10 kg is moving with a velocity of $10\,\,m{s^{ - 1}}$ when it blasts and forms two parts of mass '$9$' and '$1$' $kg$ respectively. If the '$1$'st mass is stationary, the velocity of the 2nd is

The average force necessary to stop a bullet of mass 20 g moving with a speed of 250 m/s, as it penetrates into the wood for a distance of 12 cm is

A uniform disc of mass M and radius R is mounted on a fixed horizontal axis. A block of mass m hangs from a massless string that is wrapped around the rim of the disc. The magnitude of the acceleration of the falling block (m) is

A wooden block of mass 1 kg is attached to the hook of a spring balance. The spring balance is then raised with an acceleration of $9.8{\rm{\;m}}{{\rm{s}}^{ - 2}}$. The apparent weight of the body is

A stationary radioactive nucleus decays into three particles with mass ratios $2:2:1$. The two heavier particles move at right angles to each other with equal speeds of $5 ext{ m/s}$. Find the speed of the lightest particle.