Bridge Kit Activity

Activity 1:

In Activity 1, I placed a 3x5 notecard on top of 2 blocks that were spaced 4 inches apart. Then, I simply added pennies until it collapsed. After I dropped the fifth penny on the "bridge," it collapsed. The main force that came into play was compression. Compression is the force that compresses or shortens the thing it is acting on. Our "bridge" buckled when the compressive force was exerted. Therefore, the pushing force on the "bridge" (3x5 card) was the pennies.

Here are some pictures of this activity:

Activity 2:

In Activity 2, I created 2 arches and taped them onto the same notecard from Activity 1. This time, the "bridge" held 11 coins, which is 6 more than was held in Activity 1. The main difference between the first and second activities is that there are arches on the second "bridge" that help support and evenly distribute the weight so that it could hold more weight.

Here are some pictures of this activity:

Activity 3:

In Activity 3, I added vertical and parallel supports to the "bridge" from Activity 2. This third bridge supported 32 pennies, which is 21 more than the second activity's bridge. The difference between what happened in Activities 1 and 2 and what happened here is that the pennies were supported better because the compression was distributed across and down the walls of the bridge. The stress was put on the joints and members rather than the middle of the bridge, so it held up better. The forces of compression and tension came into play in this activity. The compressive forces flowed inwards on the bridge, which eventually led it to collapse.