A cube of edge length 10 cm is just balanced at the interface of two liquids A and B . It is 6 cm in liquid B and 4 cm in liquid A. If A and B has specific gravity 0.6 and 0.4 respectively, then the mass of cube is?
(1) 240 g

(2) 360 g

(3) 480 g

(4) 540 g

Ans. would be option (3)...pls give detailed explanations...

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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