Advertisements
Advertisements
प्रश्न
A boy of mass 50 kg running at 5 m/s jumps on to a 20 kg trolley travelling in the same direction at 1.5 m/s. What is their common velocity ?
Advertisements
उत्तर
Momentum = Momentum of the boy + Momentum of the trolley
= Mass of boy × velocity of boy +Mass of trolley × Velocity of trolley
Momentum = Mass of the boy and trolley × common velocity
⇒ 280 = (50+20) × common velocity
⇒ 280 = 70 × common velocity
⇒ `280/70` = common velocity
⇒ 4 = common velocity
Hence, common velocity is 4 m/s.
APPEARS IN
संबंधित 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?
Figure shows the position-time graph of a body of mass 0.04 kg. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the body ? What is the magnitude of each impulse ?
What is the total momentum of the bullet and the gun before firing ?
Which physical quantity corresponds to the rate of change of momentum ?
State the relation between the momentum of a body and the force acting on it.
Name the principle on which a rocket works.
Explain why it is possible for a small animal to fall from a considerable height without any injury being caused when it reaches the ground.
A girl of mass 50 kg jumps out of a rowing boat of mass 300 kg on to the bank, with a horizontal velocity of 3 m/s. With what velocity does the boat begin to move backwards ?
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?
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?
