Why is the pressure on ground more when a man is walking than when he is standing ?

Why is the denstiy of nucleus more than that of the atom?

A man is moving away from a tower 41.6 m high at the rate of 2 m/sec. Find the rate at which the angle of elevation of the top of tower is changing, when he is at a distance of 30m from the foot of the tower. Assume that the eye level of the man is 1.6m from the ground.

Why the vapour pressure of a solution of glucose in water is lower than of pure water

Why is iron more useful when it is mixed with a little carbon?

Why is it dangerous to stand on the edge of the platform near the railway line when the train is passing by?