Question

A vehicle was moving at the speed of 72km/hour on seeing a boy 40 m ahead the driver applies the brake the vehicle stops in 5 seconds calculate the diastance travelled​

Answer 1

Initial velocity= 72km/hr=20m/s

Final velocity =0m/s

Time taken= 5s

Now,retardation

$\sf </p><p>= \frac{V-u} {t} \\\\\sf</p><p>= \frac{0-20} {5} \\\\\sf</p><p>=-4m/s^2 \\\\\sf</p><p>Now,by the formula, \\\\\sf</p><p>v^2=u^2+2as \\\\\sf</p><p>0=400+(-8)s \\\\\sf</p><p>400=8s \\\\\sf</p><p>s=\frac{400}{8} \\\\\sf</p><p>=50m</p><p>$

The answer is 50m by calculation..but what would have happened with that boy... Lol...