5g of a sample containing (NH₄)₂SO₄ and inert impurity (x) was boiled with excess of NaOH and NH₃ so produced was absorbed in 200 ml of 0.5 M H₂SO₄ solution in another vessel. The unreacted H₂SO₄required 400 ml of 0.4 M solution of NaOH for exact neutralisation. Calculate weight % of nitrogen in given sample

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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