A truck loaded with cannonball watermelons stops suddenly to avoid running over the edge of a washed-out bridge (see figure). The quick stop causes a number of melons to fly off the truck. One melon rolls over the edge with an initial speed vi = 12.3 m/s in the horizontal direction.
To determine what happens to the melon that rolls over the edge of the washed-out bridge, we need to analyze its motion. Specifically, we need to consider its initial velocity and the effects of gravity.
1. Initial velocity: The problem states that the melon has an initial speed of vi = 12.3 m/s in the horizontal direction. This means that the melon is rolling off the edge of the bridge with a horizontal velocity component.
2. Effects of gravity: Even though the melon has a horizontal velocity component, it is also subject to the force of gravity, which pulls it vertically downwards. This means that the melon will experience a downward acceleration due to gravity.
Now, let's see what happens to the melon:
1. Horizontal motion: Because there are no horizontal forces acting on the melon (neglecting air resistance), its horizontal velocity will remain constant. This means that the melon will continue rolling with the same horizontal speed.
2. Vertical motion: Since the melon is subject to the force of gravity, it will experience downward acceleration. This downward acceleration will cause the melon to gradually increase its vertical velocity.
As the melon rolls over the edge of the bridge, its initial horizontal speed remains constant, while its vertical speed increases. Therefore, the melon will follow a curved trajectory called a projectile motion.
In summary, the melon will continue rolling with the same horizontal speed while it falls vertically due to the force of gravity. The exact path of the melon after it rolls over the edge of the bridge can be determined using principles of projectile motion, such as considering the initial speed, the angle at which it rolls off, and the acceleration due to gravity.