Why is it difficult to hold a school bag having strap made of thin and strong string?

Why it is more difficult to revolve a stone by tying it to a longer string than by tying it to a shorter string ?

Explain why, it is difficult to hold a stainless steel tumbler containing very hot tea in the hand but a thermocol cup containing the same hot tea can be held easily.

Why do the school bags have broad shoulder straps?

Explain, why is it difficult for a fireman to hold a hose, which ejects large amount of water at a high velocity?

Statement : Should computer education be made a compulsory subject at school level by the Government? Arguments : I. No, it may be difficult to teach computers in the schools located in rural parts of the country. II. Yes, it is difficult to function without computer in the era of modernisation.