4.2 Calculation of efficiency
(a) Mass of load on bridge =
(b) Mass of bridge =
Efficiency = (a) / (b)
4.3 Discussion of bridge design after testing
1. What is your score on efficiency? If the efficiency is high/low, what went right/wrong?
Our score on efficiency is 41, the low triangle support of the bridge(deck truss) was disconnected from the main bridge, might be because we did not use enough glue and time to let it dry completely.
2. Which part of the bridge started to give way first? Explain using Physics concepts.
The first part that started to give away first is the low triangle support of the bridge, this is because the weight is held at the centre of the bridge, as more weight is placed on, the bridge bent downwards, this then causes the low triangle support to push the tension to the sides, hence pulling itself away from the bridge and due to the lack of connection of the glue, the low triangle support is disconnected from the bridge.
3. Which part of the bridge provided the most strength in the testing process? Explain using Physics concepts.
The 5 strips of deck truss on the bridge provided the most strength in the testing process as without them, the bridge would have been broken easily even with the low triangle support. It is the strongest as the tension of the bridge is the highest there, with the help of the triangle support connected to the 5 different strips, the tension is spread across the strips, hence preventing the bridge to break in half, this is why it provided the most strength as without it, the bridge would have broken into halves right away. The 5 strips is also the strongest as it is made with 4 sticks thickness that is glued together and is perpendicular to the bridge, this way of connecting allow the strips to be strong as it will be harder to bend them.