Question

1. When we experiment, we always want to think about sources of experimental uncertainty. In the lab "Measurement and Uncertainty" you learned about random errors and systematic errors. Let's think about some potential sources of uncertainty in this experiment.

   If the uncertainty is random, fill in R. If it is systematic, fill in S.

   In every trial, a student holds the picket fence so that it is tilted slightly to the left as it drops through the photogate.

   In the course of the experiment, the student holds the picket fence pretty close to vertical, but some times there is a slight tilt to either the left or right.

   One student group cannot find their picket fence. The decide to just drop a tennis ball through the photogate instead.

Answer 1

1) In every trial, a student holds the picket fence so that it is tilted slightly to the left as it drops through the photogate.

This is a systematic error.

Here, the student tilts the picket fence slightly every time the experiment is done.

The error due to this will be constant and will be almost the same for all cases.

2) In the course of the experiment, the student holds the picket fence pretty close to vertical, but some times there is a slight tilt to either the left or right.

This is a random error

Here also the student tilts the picket fence slightly while the experiment is done But there is no certainty that there will be a tilt and the direction of tilt is also random.

The error due to this will not be constant and will change for each case.

3) One student group cannot find their picket fence. The decide to just drop a tennis ball through the photogate instead.

This is a systematic error.

Here, the student uses a different material for the experiment to be done

The air resistance will be present for a ball and will tamper with the data.

The error due to this will be constant and will be almost the same for all cases.