Full figure (38 kB)Fig. 1. The model shows that two projectiles fired simultaneously and horizontally, but at different speeds, will hit the ground at the same time. (The string lengths represent vertical displacements due to gravitational acceleration.) First citation in article
Full figure (32 kB)Fig. 2. When two projectiles are fired at an upward angle, the one with the slower initial speed will hit the ground first. First citation in article
Full figure (37 kB)Fig. 3. If the projectiles are fired downward, say from a cliff into a canyon, the model shows that the one with the faster initial speed will hit the ground first. First citation in article
Full figure (38 kB)Fig. 4. The model showing the projectiles going over a "wall." Notice that the one with the slower initial speed barely clears the obstacle. First citation in article