# Momentum

## Trending Questions

**Q.**The point from where a ball of mass 2 kg is projected is taken as the origin of the co-ordinate axes. The x and y components of its displacement are given by x=6t and y=8t−5t2. Find the change in its momentum ( in 𝒌𝒈 𝒎/𝒔) from t=0 to t=2 seconds.

- 40
- 60
- 80
- 20

**Q.**A projectile of mass 4M is fired at a speed of 100 m/s at an angle of 37∘ from the horizontal. At the highest point, the projectile breaks into two parts with mass M and 3M. Mass M falls down immediately after the explosion and mass 3M lands at some horizontal distance from mass M. Choose the correct statement. (Take g=10 m/s2)

- None of the above
- Time taken by 4M to reach the highest point and time taken by 3M to land on the ground from the highest point will be the same.
- Time taken by 4M to reach the highest point and time taken by 3M to land on the ground from the highest point will be different.
- Distance covered by 4M along the horizontal ground and distance covered by 3M along the horizontal ground will be the same.

**Q.**Figure shows the variation of force acting on a body with time. Assuming the body to start from rest the variation of its momentum with time is best represented by which plot?

**Q.**A particle of mass M is moving in a horizontal circle of radius R with uniform speed V. When it moves from one point to a diametrically opposite point, its

- Kinetic energy changes by MV24
- momentum does not change.
- Momentum changes by 2MV.
- Kinetic energy changes by MV2

**Q.**Six bullets of mass 5 gm are fired from a gun of mass 5 kg. What is the speed of the gun if the speed of the bullets w.r.t. the ground is 200 m/s?

- 1.2 m/s
- 0.2 m/s
- 200 m/s
- 2006 m/s

**Q.**A lead ball strikes a wall and falls down while a tennis ball having the same mass and velocity strikes the wall and bounces back. Check the correct statement.

- The momentum of the lead ball is greater than that of the tennis ball.
- The lead ball suffers a greater change in momentum compared with the tennis ball.
- The tennis ball suffers a greater change in momentum as compared with the lead ball.
- Both suffer an equal change in momentum.

**Q.**A nucleus of mass number 'A' originally at rest emits an α particle with a speed 'v' the recoil speed of the daughter nucleus is

- 4vA+4
- 2v4−A
- vA+4
- 4vA−4

**Q.**A 1 kg stationary bomb is exploded in three parts having mass ratio 1:1:3. Parts having same mass move in perpendicular directions with velocity 30 m/s, then the velocity of bigger part will be:

- 10√2 m/s
- 10√2 m/s
- 15√2 m/s
- 15√2 m/s

**Q.**A metal cannonball of mass m rests next to a tree at the very edge of a cliff 36.0 m above the surface of the ocean. In an effort to knock the cannonball off the cliff, some children tie one end of a rope around a stone of mass 80.0 kg and the other end to a tree limb just above the cannonball. They tighten the rope so that the stone just clears the ground and hangs next to the cannonball. The children release the stone, which then swings down and makes a head-on, elastic collision with the cannonball, projecting it horizontally off the cliff. The cannonball lands in the ocean a horizontal distance R away from its initial position.

Find the horizontal component R of the cannonball's displacement as it depends on m.

**Q.**A gun (mass = M) fires a bullet (mass = m) with speed vr, relative to barrel of the gun which is inclined at an angle of 60o with horizontal. The gun is placed over a smooth horizontal surface. Find the recoil speed of the gun.

- v=Mvr2(M+m)
- v=mvr(M+m)
- v=mvr√2(M+m)
- v=mvr2(M+m)