Question

A bicycle moves with a constant velocity of $5\text{km/hr}$ for $10\text{minutes}$ and then decelerates at the rate of $1{\text{km/hr}}^2$ till it stops. Find the total distance covered by the bicycle.

• A. $\frac{75}{3}\text{km}$
• B. $\frac{55}{3}\text{km}$
• C. $\frac{50}{3}\text{km}$
• D. $\frac{40}{3}\text{km}$

Answer 1

The correct option is D $\frac{40}{3}\text{km}$

Distance covered in $10\text{minutes}$,
$S_1=vt=5\times \frac{10}{60}=\frac{5}{6}\text{km}$

Distance covered during deceleration,
$S_2=\frac{v^2-u^2}{2a}=\frac{0^2-5^2}{2(-1)}=\frac{25}{2}\text{km}$

So, total distance covered,
$S=S_1+S_2=\frac{5}{6}+\frac{25}{2}=\frac{40}{3}\text{km}$