A rocket has positive velocity v(t) after being launched upward from an initial height of 0 feet at time =0 seconds_ The velocity of the rocket is recorded for selected values of over the interval 0 < t < 80 seconds as shown in the table below 10 20 30 40 50 60 70 80 seconds v(t) (feet_per_second_ 22 29 35 40 44 47 49 Use a midpoint Riemann sum with 3 subintervals of equal length to approximate v(t)dt _ b) Using correct units, explain the meaning of v(t)dt in terms of the rocket's flight
