What is the numerical ratio of average velocity to average speed of an object when it is moving along a straight path?

$A$ moving body is covering a distance directly proportional to the square of time. The acceleration of the body is

$A$ train $100 \, m$ long is moving with a velocity of $60 \, km/h$. Find the time it takes to cross a bridge $1 \, km$ long.

Name a physical quantity that essentially changes as a body moves.

$A$ frog hops along a straight line path from point $A$ to point $B$ in $10 \, s$ and then turns and hops to point $C$ in another $5 \, s$. Based on the provided number line,calculate the average speed and average velocity of the frog for the motion between: $(a)$ $A$ to $B$ $(b)$ $A$ to $C$ (through $B$).

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$)