Name the force which is responsible for change in position or state of an object.

Give one example for each of the type of motion when
$(i)$ acceleration is in the direction of motion.
$(ii)$ acceleration is against the direction of motion.
$(iii)$ acceleration is uniform.

$A$ cyclist driving at $5\, m s^{-1}$ picks up a velocity of $10\, m s^{-1}$ over a distance of $50\, m$. Calculate $(i)$ acceleration $(ii)$ time in which the cyclist picks up the above velocity.

What is the average velocity of a particle when it returns to the starting point? Can its average speed be zero?

State whether the following statement is true or false:
$A$ motion is said to be uniform if $x \propto t^{2}$.

The velocity-time graph of a body is as shown. What type of motion does the body possess?