What is the nature of the displacement-time graph of a body moving with constant velocity?

The numerical ratio of displacement to distance for a moving object is

$A$ body is moving along a circular path of radius $R$. Find the displacement of the body when it completes half a revolution.

Account for the following:
$(a)$ Name the quantity which is measured by the area occupied below the velocity$-$time graph.
$(b)$ Give an example of an object moving in a certain direction with acceleration in the perpendicular direction.
$(c)$ Under what condition is the magnitude of average velocity of an object equal to its average speed?
$(d)$ Give an example of uniformly accelerated motion.
$(e)$ $A$ body is moving along a circular path of radius $r$. What will be the distance and displacement of the body when it completes half a revolution?

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$)

Write any two equations of motion for a body having uniform acceleration.