State whether the following statement is true or false:
Velocity and speed are measured in different units.

$A$ person standing at $A$ goes to $B$ by following any of the paths $1, 2$ or $3$. Which path can we measure to find the average velocity?

Why is the motion of an athlete moving along a circular path considered an accelerated motion?

$(a)$ Define circular motion.
$(b)$ "Uniform circular motion is an accelerated motion". Justify this statement with reason.
$(c)$ An artificial satellite is moving in a circular orbit of radius $42250 \, km$. Calculate its speed if it takes $24 \, h$ to revolve once around the Earth.

What is a velocity-time graph? State how it can be used to find:
$(i)$ The acceleration of a body.
$(ii)$ The displacement of the body.
$(iii)$ The distance travelled in a given time.

Name the physical quantity which corresponds to the rate of change of momentum.