Conservation of Momentum

Q.

What are collisions? Explain the possible types of collisions.

Q. The SI unit of impulse is

1. N
2. N-s
3. N-m
4. N/m

Q.

Two objects of masses $100\mathrm{g}$ and $200\mathrm{g}$ are moving along the same line and direction with velocities of $2\mathrm{m}/\mathrm{s}$ and $1\mathrm{m}/\mathrm{s}$ respectively. They collide and after the collision, the first object moves at a velocity of $1.67\mathrm{m}/\mathrm{s}$. Determine the velocity of the second object after the collision.

Q.

A car of mass 1500 kg travelling at 25 m/s collides with another car B of mass 1000 kg travelling at 15 m/s in the same direction after the collision, the velocity of car B will be

Q.

Rockets work on the principle of conservation of:

1. Momentum

2. Mass

3. Energy

4. Impulse

Q.

State the law of conservation of momentum

Q.

Prove Newton's first and third law of motion using Newton's second law of motion

Q.

A ball of mass 5 kg moving at 3 m/s collides with another ball of mass 3 kg moving at 5 m/s in the same direction. If the balls move together after the collision in the same direction, find their common velocity.

1. 7.5 m/s

2. 5 m/s

3. 6.25 m/s

4. 3.75 m/s

Q.

Why is it difficult for a fireman to hold a hose which ejects large amount of water at a high velocity ?

Q. A fielder pulls his hands back gradually with the moving ball while holding a catch. Why does he do this?

1. It reduces the impact of catching the fast moving ball.
2. It reduces the frictional force between hand and the ball.
3. It increases the momentum of the ball.
4. It increases the speed of ball suddenly.

Q.

A girl of mass 40 kg jumps with a horizontal velocity of 5 m/s onto a stationary cart with frictionless wheels. The mass of the cart is 3 kg. What is her velocity as the cart starts moving? Assume that there is no external unbalanced force working in the horizontal direction.

Q.

What Is Impulsive Force Example?

Q.

The dimensional formula for impulse is _______.

Q.

Describe FPS system.

Q.

Find the recoil velocity of a gun having mass equal to 5 kg, if a bullet of 25 g acquires the velocity of 500 m/s after firing from the gun.(in m/s)

1. 25 m/s

2. 2.5 m/s
3. 10 m/s
4. 5 m/s

Q.

The concept of recoil velocity of gun

Q.

A bullet of mass m moving with a velocity $v$ is fired into a large wooden block of mass $M$. If the bullet remains embedded on the wooden block, the velocity of the (block + bullet) system is

1. $\frac{M}{m+M}v$

2. $\frac{m}{m+M}v$

3. $\frac{M}{M-m}v$

4. $\frac{m}{M-m}v$

Q.

Which principle is used in hydraulic turbines?

Q.

A boy of 50kg mass is running with a velocity of 2 m/s. He jumped into a stationary cart of 2kg while running. Find the velocity of cart after the boy jumped into it. (in m/s)

1. 1.52 m/s

2. 2.3 m/s
3. 3.25 m/s
4. 1.92 m/s

Q.

A bullet having a mass of 10 g and moving with a speed of 1.5 $m{s}^{-1}$, penetrates a thick wooden plank of mass 90 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.

1. $0.10m{s}^{-2}$

2. $0.10m{s}^{-1}$

3. $0.15m{s}^{-1}$

4. $0.15m{s}^{-2}$

Q. What is the conservation of linear momentum under what conditions can this concept be applied?

Q.

How does a karate player break a slab of ice with a single blow?

Q.

If a car and truck are moving with same momentum , the velocity of car is ________________ than the velocity of truck.

Q.

A body of mass 1 kg strikes elastically with another body at rest and continues to move in the same direction with one fourth of the initial velocity. What will be the mass of the other body ?

1. 0.6 kg

2. 0.4 kg

3. 0.3 kg

4. 0.2 kg

Q.

A body of mass 300 g kept at rest breaks into two parts due to internal forces. One part of mass 200 g is found to move at a velocity of $12m{s}^{-}1$towards the east.

The velocity of the other part will be?

$east\Rightarrow +ve;west\Rightarrow -ve$

1. $24m{s}^{-}1$ towards west

2. $14m{s}^{-}1$ towards east

3. $24m{s}^{-}1$ towards east

4. $54m{s}^{-}1$ towards south

Q.

A man is standing on a boat in still water if he walks towards the show the boat will

A.)move away from the Shore B.)remains stationary C.) move towards the shore or D.)sink

Q.

Impulse is the product of force and ___________.

Q.

The total momentum of a system always remain unchanged before and after the collision regardless of the external forces acting on the system.

1. True

2. False

Q. Two objects of mass $1.5kg$ each are moving towards each other in the same straight line. Before the collision, the velocity of each object is $2.5m{s}^{–1}$, after which they stick together. What will the velocity of the combined object be after collision?

Q. A bomb of mass 9 kg explodes into two pieces of masses 3 kg and 6 kg. the velocity of mass 3 kg is 15 metre per second. calculate the kinetic energy of mass 6 kg.