Question

Over a short interval time t=0 the coordinate of an automobile in meters is given by x(t)=8t2-4t+6 were "t" in second s. At the end of 2s the velocity of the automobile is: A.28m/s B. 36m/s C. 10m/s D. 23m/s

Answer 1

Velocity is the time derivative of position: v(t) = dx/dt = 16t − 4.
At t = 2 s: v = 16(2) − 4 = 32 − 4 = 28 m/s.

Answer: A. 28 m/s.