Question Detail
Question
The displacement s of a car as a function of time t is given as s(t) = (3t² - 2t + 1) m. Find its velocity at time t = 4 s. At what time will the velocity of the body become zero?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Velocity v(t) = ds/dt = 6t - 2. At t=4 s, v = 6*4 - 2 = 24 - 2 = 22 m/s. Set v=0: 6t - 2 = 0 => t = 2/6 = 1/3 = 0.333 s.
Hint
Differentiate to get velocity, then solve for t when velocity is zero.