Q: A vehicle starts moving along a straight-line path from rest. In first t seconds it moves with an acceleration of 2 m/s² and then in next 10 seconds it moves with an acceleration of 5 m/s². The total distance travelled by the vehicle is 550 m. The value of time t is
(a)10 s
(b)13 s
(c)20 s
(d)25 s
Answer pending verification