A person standing on the edge of a well throws a stone vertically upwards with an initial velocity 5 ms⁻¹. The stone goes up, comes down and falls in the well making a sound. If the person hears the sound 3 s after throwing, the water is at a depth from ground given by (neglect time of travel for the sound and take g = 10 ms⁻²)?

• A.

  1.25 m

• B.

  21.25 m

• C.

  30 m

• D.

  32.550 m

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.

11

21

31

41