The Sign of the Sine

摘要

If one plots the speed of the pendulum as it swings back and forth, the graph would be a sine wave. At the top of the arc, the speed is zero. Then it begins to travel faster and faster until the bottom of the arc. After reaching the bottom, it begins to slow down until it hits the other top of the arc and the speed goes to zero again. The process reverses as it begins to accelerate in the opposite direction. The resultig graph (Figure 1) shows the speed of the pendulum versus time.