The maximum possible acceleration of a train starting from rest and moving on straight track is 10m/s^2 and maximum possible retardation is 5m/s^2. The maximum speed that train can achieve is 85m/s. Minimum time in which the train can complete a journey of 1000m ending at rest, is n*(sqrt2)/(sqrt3) sec, where n is integer. Find n?

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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