question_answer

A car is standing 200 m behind a bus, which is also at rest. The two start moving at the same instant but with different forward accelerations. The bus has acceleration \[2\,m/{{s}^{2}}\] and the car has acceleration \[4\,m/{{s}^{2}}\]. The car will catch up with the bus after at time of -   [JEE Online 09-04-2017]

A) \[\sqrt{120}\,s\]

B) \[15\,s\]

C) \[\sqrt{110}\,s\]

D) \[10\sqrt{2}\,s\]

Correct Answer: D

Solution :

[d]

\[{{a}_{CB}}=2\,m/{{s}^{2}}\]

\[200\,=\frac{1}{2}\,\times 2{{t}^{2}}\]

\[t=10\sqrt{2}\] second