Why does a ball floating on water bobs up and down, if pushed down and released ?

Why does a greased razor blade float on the surface of water ?

Why are multiple colours observed over a thin film of oil floating on water? Explain with the help of a diagram.

A boat carring steel balls is floating on the surface of water in tank. If the balls are thrown into the tank one by one, how will it affect the level of water?

A body is just floating on the surface of a liquid. The density of the body is same as that of the liquid. The body is slightly pushed down. What will happen to the body?

Study the following activity and answer the questions: Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.

Discuss the directions of force and of displacement in each of the following cases: Walking up and down a staircase, climbing a tree.

Answer the following question : Why does it happen ? If a stationary bus suddenly speeds up, passengers are thrown in the backward direction.

Answer the following : Why does the heat in the water, heated to building, slowly decrease once it is taken off the flame? Where does this heat go?

According to Newton's law of gravitation, the earth's gravitational force is higher on an object of larger mass. Why doesn't that object fall down with higher velocity as compared to an object with lower mass ?