Advertisements
Advertisements
प्रश्न
A shell of mass 0.020 kg is fired by a gun of mass 100 kg. If the muzzle speed of the shell is 80 m s–1, what is the recoil speed of the gun?
Advertisements
उत्तर
Mass of the gun, m2 = 100 kg
Mass of the shell, m1 = 0.020 kg
initial velocities of both the shell and the gun are zero u1 = u2 = 0
After firing, the speed of the shell, v1 = 80 m s-1
Let v2 represent the recoil velocity of the gun. Following the principle of conservation of momentum,
m1v1 + m2v2 = m1u2 + m2u2
0.02 x 80 + 100v2 = 0.02 x 0 + 100 x 0
`v_2 = - 0.02xx80/100 = -0.016 "ms"^(-1)`
APPEARS IN
संबंधित प्रश्न
A stream of water flowing horizontally with a speed of 15 m s–1 gushes out of a tube of cross-sectional area 10–2 m2, and hits a vertical wall nearby. What is the force exerted on the wall by the impact of water, assuming it does not rebound?
Name the physical quantity which is considered to be a measure of the quantity of motion of a body.
Name the physical quantity whose unit is kg.m/s.
Explain how, a karate player can break a pile of tiles with a single blow of his hand.
Calculate the change in momentum of a body weighing 5 kg when its velocity decreases from 20 m/s to 0.20 m/s.
A plastic ball and a clay ball of equal masses, travelling in the same direction with equal speeds, strike against a vertical wall. From which ball does the wall receive a greater amount of momentum ?
A man throws a ball weighing 500 g vertically upwards with a speed of 10 m/s.
- What will be its initial momentum ?
- What would be its momentum at the highest point of its flight ?
Fill in the following blanks with suitable words :
In collisions and explosions, the total _____________ remains constant, provided that no external _____________ acts.
A 10 g bullet travelling at 200 m/s strikes and remains embedded in a 2 kg target which is originally at rest but free to move. At what speed does the target move off ?
A body of mass 2 kg is at rest. What should be the magnitude of force which will make the body move with a speed of 30 m/s at the end of 1 s ?
A gun of mass 3 kg fires a bullet of mass 30 g. The bullet takes 0.003 s to move through the barrel of the gun and acquires a velocity of 100 m/s. Calculate:
- the velocity with which the gin recoils.
- the force exerted on gunman due to recoil of the gun
Name the law involved in the following situation :
the sum of products of masses and velocities of two moving bodies before and after their collision remains the same.
Explain why, a cricket player moves his hands backwards while catching a fast cricket ball.
Why would an aircraft be unable to fly on the moon ?
A man wearing a bullet-proof vest stands still on roller skates. The total mass is 80 kg. A bullet of mass 20 grams is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is then the velocity of the man?
Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed v again before striking the ground. It implies that the magnitude of the initial and final momentums of the ball are the same. Yet, it is not an example of conservation of momentum. Explain why?
Two billiard balls A and B, each of mass 50 g and moving in opposite directions with speed of 5 ms–1 each, collide and rebound with the same speed. If the collision lasts for 10–3 s, which of the following statements are true?
- The impulse imparted to each ball is 0.25 kg ms–1 and the force on each ball is 250 N.
- The impulse imparted to each ball is 0.25 kg ms–1 and the force exerted on each ball is 25 × 10–5 N.
- The impulse imparted to each ball is 0.5 Ns.
- The impulse and the force on each ball are equal in magnitude and opposite in direction.
A girl riding a bicycle along a straight road with a speed of 5 ms–1 throws a stone of mass 0.5 kg which has a speed of 15 ms–1 with respect to the ground along her direction of motion. The mass of the girl and bicycle is 50 kg. Does the speed of the bicycle change after the stone is thrown? What is the change in speed, if so?
A monkey of mass 20 kg rides on a 40 kg trolley moving with constant speed of 8 m/s along a horizontal track If the monkey jumps vertically to grab the overhanging branch of a tree, the speed of the trolley after the monkey has jumped off is ______.
