Explain why the handle of a door is placed as far as possible from the hinges. Explain why it is easier to loosen a tight nut using a spanner with a long handle than the one with a short handle.

A student wearing sharp pointed heeled shoes is likely to damage a soft wooden floor. Explain.

Describe how the oil patch is formed in an oil drop experiment. 

Give a reason why mass of a body is constant everywhere.

What is the essence of an oil molecule in hydraulic machines?

When I look at the tyres of a moving vehicle in a movie the look as if they are moving in the opposite direction. How can we explain this phenomenon/effect?

the initial velocity of a body 20kg is 4m/s. how long would a constant force of 5N act on the body to double its kinetic energy