Conservation of Momentum

Q.

What would be the relation between magnitude of velocity of the gun and bullet after firing, if the mass of gun is less than the mass of bullet? Assume no external force is acting on the gun bullet system.

1. None of the above

2. Velocity of gun is higher than the velocity of bullet

3. Velocity of bullet is higher than the velocity of gun

4. Velocity of gun = velocity of bullet

Q. If a bomb at rest explodes and splits into two equal fragments, the fragments will move in:

(a) One direction and with equal velocities.
(b) Opposite directions with different velocities.
(c) One direction with different velocities.
(d) Opposite directions with equal velocities.

[1 mark]

Q. A bullet of 5 g is fired from a pistol of 1.5 kg. If the recoil velocity of pistol is $1.5m{s}^{-1}$, what is the final momentum of the pistol?

1. 10 $\frac{kgm}{s}$
2. 2.5 $\frac{kgm}{s}$
3. 1.5 $\frac{kgm}{s}$
4. 2.25 $\frac{kgm}{s}$

Q.

Consider the situation where a gun is kept on a frictionless surface and is being operated remotely by a group of engineers. If the mass of the gun is more than that of the bullet, what would be the relation between their velocities?

1. Velocity of gun = velocity of bullet

2. Velocity of gun is higher than the velocity of bullet

3. Cannot be determined.

4. Velocity of bullet is higher than the velocity of gun

Q.

A bullet of $5g$ is fired from a pistol of $1.5kg$. If the recoil speed of pistol is $1.5m{s}^{-1}$, find the velocity of bullet.

1. $400m{s}^{-1}$

2. $450m{s}^{-1}$

3. $600m{s}^{-1}$
4. $500m{s}^{-1}$

Q.

Calculate the recoil velocity of a gun having mass equal to 5 kg, if a bullet of 25 g acquires the velocity of $500m{s}^{-1}$ after firing from the gun.

1. $25m{s}^{-1}$

2. $2.5m{s}^{-1}$
3. $10m{s}^{-1}$
4. $5m{s}^{-1}$

Q. Two masses ${\text{m}}_1$ and ${\text{m}}_2$ collide with each other. Before the collision, the velocities are ${\text{u}}_1$ and ${\text{u}}_2$ respectively. After the collision, the velocities are ${\text{v}}_1$ and ${\text{v}}_2$ respectively. The total final momentum after collision is given by:

1. ${\text{m}}_1{\text{v}}_2+{\text{m}}_2{\text{v}}_1$
2. ${\text{m}}_1{\text{u}}_2+{\text{m}}_2{\text{u}}_1$
3. ${\text{m}}_1{\text{u}}_1+{\text{m}}_2{\text{u}}_2$
4. ${\text{m}}_1{\text{u}}_1+{\text{m}}_2{\text{v}}_2$

Q.

A boy of $50kg$ mass is running with a velocity of $2m{s}^{-1}$. He jumped into a stationary cart of $2kg$ while running. Find the velocity of the cart after the boy jumped into it.

1. 1.52 $\frac{m}{s}$

2. 2.3 $\frac{m}{s}$
3. 1.92 $\frac{m}{s}$
4. 3.25 $\frac{m}{s}$

Q. When a bullet is fired from a pistol, in which direction the pistol moves (ignore the force exerted by hand)?

1. It will be in the same position as before.
2. Opposite to the bullet's direction.
3. Perpendicular to the bullet's direction.
4. Along the bullet's direction

Q. A block of mass $1kg$ travelling in a straight line with a velocity of $10m{s}^{-1}$ collides with and sticks to a stationary wooden block of mass 5 kg.
Then they both move off together in the same straight line. Calculate the total momentum just before the impact, just after the impact and the velocity of the combined object.

1. $10kgm{s}^{-1}$, $10kgm{s}^{-1}$, $2m{s}^{-1}$
2. $10kgm{s}^{-1}$, $10kgm{s}^{-1}$, $1.67m{s}^{-1}$
3. $5kgm{s}^{-1}$, $10kgm{s}^{-1}$, $2m{s}^{-1}$
4. $10kgm{s}^{-1}$, $20kgm{s}^{-1}$, $1.67m{s}^{-1}$