$A$ racing car has an acceleration of $4\, m s^{-2}$. What distance will it cover in $20\, s$ after the start (in $, m$)?

$A$ 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.

$A$ piece of stone is thrown vertically upwards. It reaches its maximum height in $3 \ s$. If the acceleration of the stone is $9.8 \ m s^{-2}$ directed towards the ground,calculate the initial velocity of the stone with which it is thrown upwards. Find the maximum height attained by it.

$A$ train is travelling at a speed of $90\, km \,h^{-1}$. Brakes are applied so as to produce a uniform acceleration of $-0.5\, m s^{-2}$. Find how far (in $m$) the train will go before it is brought to rest.

$A$ body is thrown vertically upward with velocity $u$,the greatest height $h$ to which it will rise is,

$A$ ball thrown up vertically returns to the thrower after $6\, s$. Find
$(a)$ the velocity with which it was thrown up,
$(b)$ the maximum height it reaches,and
$(c)$ its position after $4\, s$.