A fighter jet moving in a vertical circle iwth a consatnt radius R. The centre of circle is at a height 2R from an obsever on the ground .The observer recieves maximum frequency of sound produced by the plane when it is nearest to him .if speed of sound in air is v,speed of fighter jet is

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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