Give reason for the following.
a) When a carpet is beaten with a stick dust comes out.
b) Safety belts are provided in vehicles.
c) Boat moves backward when a man jumps out of it.
d) When a bullet is fired from a gun. The gun recoils.
Answers
Answer:
1) When the carpet is beaten with a stick, the stick exerts a force on the carpet which sets it in motion. The inertia of the dust particles residing on the carpet resists the change in the motion of the carpet. ... This is why the dust comes out of the carpet when beaten.
2) All the cars are provided with seat belts to prevent accidents. The job of the seat belts is to hold the passenger in place so the passenger is almost part of the car which prevents the passenger from flying forward as the car stops abruptly in the case of a collision.
3) The boat exerts an equal force in the forward direction which helps him to move forward. The force exerted by the boat is called reaction. So due to this reaction force the boat moves backward due to the force exerted by the man. So that's why if a man jumps out from a boat, the boat moves backward.
4) When a bullet is fired from a gun, the gun exerts a force on the bullet in the forward direction. This is force is called as the action force. The bullet also exerts an equal and opposite force on the gun in the backward direction. Therefore a gun recoils when a bullet is fired from it.