Physics Balsa Bridge Building Contest: INSTRUCTIONS TO TESTERS

INSTRUCTIONS TO TESTERS

PHYSICS BALSA BRIDGE BUILDING

1. Four testers should be on duty all the time. One pours sand and adds weights One passes buckets of sand to the pourer Two are ready to steady the bucket and catch it

2. Consistency is important. This means we attempt to be fair to all contestants by adding sand at roughly the same rate for all bridges. However, because some bridges are much stronger than others, we must also use weights.

3. Before adding weight, ask the contestant(s) to approve the positioning of the bridge and test frame.

4. Start off each bridge with one 10 lb weight, unless there is reasonable doubt that the bridge will support that weight. For some bridges you will be directed to add additional weight to start. Strong bridges will likely require up to 80 lbs of weights. These will be added in the manner large first, smaller second.

5. When adding sand, pour it in evenly, distributing the sand around the bucket evenly. Use the mister to keep the dust levels down.

6. Wear safety glasses when working around the bridge testing area.

7. Always attempt to "save" a bridge from complete destruction by minimizing the fall distance for the bucket.

8. Watch for evidence of bridge failure. Failure of any component (cracking) is a condition for termination.

9. Take care not to bump the testing tables, especially when the bridge is under heavy load.

10. When a bridge fails, the entire bucket and its contents must be weighed. The contents are to include the test frame and steel bolt. Remove any balsa wood pieces from the bucket before weighing. Note the mass reading, and ensure that one of the judges records this value.

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