State whether the following statement is true or false:
Kinematics deals with the motion of non-living objects without taking into account the cause of their motion.

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

Under what condition will the magnitude of the displacement be equal to the distance travelled by an object?

Suppose a boy is enjoying a ride on a merry-go-round which is moving with a constant speed of $10 \, ms^{-1}$. It implies that the boy is

The following figure is the speed-time graph for a rocket from the moment when the fuel starts to burn,i.e.,at time $t=0$.
$(a)$ State the acceleration of the rocket at $t=0$.
$(b)$ State what happens to the acceleration of the rocket between $t=5 \, s$ and $t=60 \, s$.
$(c)$ Calculate the acceleration of the rocket at $t=80 \, s$. Give a reason for your answer.
$(d)$ The total mass of the rocket at $t=80 \, s$ is $1.6 \times 10^{6} \, kg$. Calculate the resultant force on the rocket at this time. Give a reason for your answer.

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