A railroad car is moving along a straight frictionless track. In each of the following cases, the car initally has a total mass (car and contents) of 200kg and is travelling with a velocity 4m/s. Find the final velocity of the car in each of the 2 cases: (a) A 20Kg mass is thrown sideways out of the car with a velocity of 2m/s relative to the car?

(b) A 20kg mass is thrown into the car with a velocity of 6m/s relative to the ground and opposite in direction to the velocity of the car ?

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

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