A projectile has the same range for two angles of projection. If the time of flight in two cases are t₁ and t₂ then(a) the range of the projectile is

1. 1/2gt₁t₂
2. 1/4 gt₁t₂
3. gt₁t₂
4. 1/8gt₁t₂

_​b)the velocity of projection of projectile is

1. 1/2g(t₁+t₂)
2. 1/4g(t₁+t₂)
3. 1/2g(t²₁+t²₂)^1/2
4. 1/2g(t₁²+t₂²)

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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