Q:- If a person with a load jumps from a higher building then do you know what will be the load experienced by him?

Ans:- If you know the concept of acceleration of the gravity, then the to understand the reason will be easier for you.

The answer to the query is Zero, because the acceleration of his fall is equal to the acceleration due to the gravity of the earth.

Q:- Why is standing in double decker buses or boats not allowed, particularly in the upper floor of buses?

Ans:- This is due to the concept of the centre of the gravity. When the boat or bus tilts, the centre of gravity of the boat or bus is lowered and it is likely to overturn. Therefore the standing in boat or bus is not allowed.

Q:- Why the salt is added in water while boiling grams?

Ans:- If you know that salt helps in increase of boiling point of water and if you further know that more boiling point means, easier to cook the food, then you can guess the answer.

That is by addition of salt the boiling point of water gets raised which helps in cooking.

Q:-Why is the boiling point of sea water more than that of pure water?

Ans:- As already discussed in last question that salt helps in increase of boiling point of water and Sea water contains lots of salt and other impurities with different boiling points, which raise the boiling point of sea.