Question

Q1 what indicates the motion of earth
Q2 when a person jumps from a boat on the shore the boat starts moving on the opposite direction explain this phenomenon on the basis of principle of conservation of linear momentum

Answer 1

(1) Rotation of earth indicates the motion of earth which causes day and night.

(2) When a boat and a man stand still initially, the total momentum of the boat and the man is zero. As the man jumps from the boat to the shore, momentum is gained by him in the forward direction.

The boat also gains similar amount of momentum in the opposite direction to conserve momentum. That is why when a man jumps out of a boat to the shore, the boat starts moving in opposite direction.