As your friend skateboards down a hill again, you measure their velocity at 1.0-second intervals. You record the following data: {(0.0 s, 0.5 m/s), (1.0 s, 2.6 m/s), (2.0 s, 4.7 m/s),
(3.0 s, 6.8 m/s), (4.0 s, 8.9 m/s)}. Determine your friend’s acceleration.