The speed-time graphs of two cars are represented by $P$ and $Q$ as shown below

$(a)$ Find the difference in the distance travelled by the two cars (in $m$ ) after $4\, s$.

$(b)$ Do they ever move with the same speed ? If so when ?

$(c)$ What type of motion car $P$ and $Q$ are undergoing ?

Write true or false for the following statements

A motion is said to be uniform, if $x \propto t^{2}$

A particle is moving in a circular path of radius $r$. The displacement after half a circle would be :

A cyclist driving at $36\, km h^{-1}$ stops his cycle in $2\, s$ by the application of brakes. Calculate $(i)$ retardation $(ii)$ distance covered during the application of brakes.

If the displacement of a body is proportional to the time elapsed, what type of motion does the body possess ?