Question

A car starting from rest attains a maximum speed of 100 kmph in 20 seconds. what will be its acceleration assuming it is uniform? 1. 1.0 m/s2 2. 1.4 m/s2 3. 1.8 m/s2 4. 2.0 m/s2

Answer 1

u=0 initial velocity
v=100km/h=250/9 m/s

$use \: formula \: \\ \\ v = u + at \\ \frac{250}{9} = 0 + a \times 20 \\ a = \frac{250}{180} \\ a = 1.388m {s}^{ - 2}$
which is approximately equal to 1.4m/s^-2