Question

a bicyle moves with a constant velocity of 5 km/hr for 10 minutes and then decelerates at the rate of 1km/hr²till it stops. find the total distance covered by the bicycle

Answer 1

Here, initial velocity, $u=5km/h$
Time, $t=10minute=\frac{10}{60}=0.167hour$
Deceleration, $a=-1km/h^2$

First, the bicycle moves with a constant velocity of 5 km/h. So,
Distance, $s=ut=5\times 0.167=0.835km$

Now, since the bicycle decelerate at the rate of 1 $km/h^2$ till it stops, so

$s=\frac{v^2-u^2}{2a}=\frac{0-5^2}{2\times \left(-1\right)}=12.5km$

So, total distance $=0.835+12.5=13.34km$