A race car moves such that its position fits the relationship
x(t) = (4.7 m/s)t + (0.77 m/s^3) t^3
where x is measured in meters and t in seconds.
Approximate the instantaneous velocity at
2 s, using a centered time interval of 0.1 s.
Answer in units of m/s

Approximate the instantaneous velocity by computing the average velocity of the car over the interval [1.95, 2.05] (i.e. the interval centered at t = 2 s with length 0.1 s).

By definition, average velocity is given by

v = ∆x / ∆t

So we have

v(2 s) ≈ (x(2.05 s) - x(1.95 s)) / (0.1 s) ≈ 13.94 m/s

d.7.5cm is your answer

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