Question

A car accelerates uniformly from 36 km h -1 to 72 km -1 in 5s . Calculate the acceleration

Answer 1

ɧeՎ ԲՐɿeՌԺ


$v = u + at$



$72 = 36 + 5a$



$5a = 36 \\ \\ a = \frac{36}{5} = 7.2m \: persec {}^{2}$



Hope it helps you


@ Prabhudutt

Answer 2

$We \: are \: given \: that$

$u = 18 \: km \: {h}^{ - 1} = 5 \: m {s}^{ - 1} \\ v = 36 \: km {h}^{ - 1} = 10 \: m {s}^{ - 1} \\ t = 5 \: s$

i)$a = \frac{v - u}{t} \\ = \frac{10 \: m \: {s}^{ - 1} - 5 \: m {s}^{ - 1} }{5s} \\ = 1 \: m \: {s}^{ - 2}$

ii)$s = u \: t + \frac{1}{2}a \: t^{2} \\ = 5m \: {s}^{ - 1} \times 5 \: s + \frac{1}{2} \times 1 \: m {s}^{ - 2} \times (5 \: s){2} \\ = 25 \: m + 12.5 \: m \\ = 37.5 \: m$

$The \: acceleration \: of \: the \: car \: is \: 1 \: m \: {s}^{ - 2}$

$and \: the \: distance \: covered is \: 37.5 \: m$