$(a)$ Differentiate between distance and displacement.

$(b)$ Under what conditions is the magnitude of average velocity of an object equal to its average speed ?

Two cars moving in opposite directions cover same distance $'d'$ in one hour. If the cars were moving in north$-$south direction, what will be their displacement in one hour ?

Write true or false for the following statements

A quantity which can be completely specified by magnitude as well as direction is called a scalar quantity.

Ravi told his friend that his house is $1 \,km$ toward south from the main Post Office. Express displacement and the distance moved by the friend from the Post Office when he arrives at Ravi's house. Mention the reference point chosen by you.

A body thrown in the vertically upward direction rises upto a height $'h^{\prime}$ and comes back to the position of its start.

Calculate :

$(a)$ the total distance travelled by the body and

$(b)$ the displacement of the body. Under what condition will the magnitude of the displacement be equal to the distance travelled by an object ?