...You're riding an amusement park ride

Question

You’re riding an amusement park ride down waterfalls, and you accelerate with a mass of 59 kg a combination of you and the ride from 4.04 m/s to 10.98 m/s in 4 s. How much power does it require?

Answer 1

I will assume that we are not including gravitational acceleration here, especially because it is much greater than calculating acceleration from the givens: a = (v - v_o) / t = (10.98 - 4.04) / 4 = 1.73₅ m/s² [I retain at least one more figure than # of sig figs (assuming that "4 s" is precise)]. Then force F = ma = 59a = 10₂.₄ N. From kinematics, Δx = 1/2 (v_o + v) t = 1/2 (15.02)(4) = 30.04 m.

Work W = F Δx = 30₇₅ J and power P = W / t = 770 W.