$A$ motorcyclist drives from $A$ to $B$ with a uniform speed of $30\, km\, h^{-1}$ and returns back with a speed of $20\, km\, h^{-1}$. Find its average speed (in $km\, h^{-1}$).

Four cars $A$,$B$,$C$ and $D$ are moving on a levelled road. Their distance versus time graphs are shown in the figure. Choose the correct statement.

$(a)$ Differentiate between speed and velocity.
$(b)$ When is a body said to have uniform velocity?
$(c)$ How can we describe the position of an object? Illustrate with a suitable example.

An artificial satellite is moving in a circular orbit of radius nearly $42,250 \, km$. Calculate its linear velocity, if it takes $24 \, \text{hours}$ to revolve around the Earth. (in $ km/s$)

Which of the following figures (Fig.) represents uniform motion of a moving object correctly?

$A$ body thrown in the vertically upward direction rises up to a height $h$ 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?