- Home
- Standard 11
- Physics
2.Motion in Straight Line
medium
A bus starts moving with acceleration $2\,m / s ^2$. A cyclist $96\,m$ behind the bus starts simultaneously towards the bus at $20\,m / s$. After $........\,s$ time will he be able to overtake the bus.
A
$4$
B
$8$
C
$12$
D
$16$
Solution
(b)
Let after a time t, the cyclist overtake the bus. Then $96+\frac{1}{2} \times 2 \times t^2=20 \times t$ or $t^2-20 t+$ $96=0$
$\therefore t =\frac{20 \pm \sqrt{400-4 \times 96}}{2 \times 1}$
$=\frac{20 \pm 4}{2}=8\,sec . \text { and } 12\,sec .$
Standard 11
Physics