Question

An aeroplane lands at 432 km/hr and stops after covering a runaway of 4 km. Calculate (i) acceleration (ii) time in which it comes to rest.

Answer 1

$a = \frac{v - u}{t} \\ where \: a = acceleration \: v = final \: velocity \: u = initial \: velocity \: t = time \: taken$
$v = 0 \: finally \: plain \: comes \: in \: rest \\ u = 432 \\ t = 4km$
$a = \frac{0 - 432}{4}$
$a = \frac{ - 432}{4}$
$a = - 108km \: per \: hr$
but I don't know (ii) answer