Question

A car accelerates from zero to a speed of 36 km/h in 15 s.

i.

Calculate the acceleration of the car in m/s².

ii.

If the acceleration is assumed to be constant, how far will the car travel in 1 minute ?

iii.

Calculate the speed of the car after 1 minute.

Answer 1

Given:

$v_i=0\:\rm m/s$

$v_f=36\:\rm km/h=10\:\rm m/s$

$t=15\:\rm s$

$t_1=60\:\rm s$

(i)

$$a=\frac{v_f-v_i}{t}=\frac{10-0}{15}=0.67\:\rm m/s^2$$

(ii)

$$d=v_it_1+at_1^2/2\\ =0*60+0.67*60^2/2=1200\:\rm m$$

(iii)

$$v=v_it_1+at_1\\ =0*60+0.67*60=40\:\rm m/s$$