Thrice Measured Pendulum Demonstration

 

This demonstration is about reaction time. Any time human reaction is involved in a measurement, their reaction time is a source of uncertainty. Useful for pointing out that "human error" is not a specific enough description at the university level.

LoggerPro Pendulum       

Used in Lab:

This demonstration is used in the Uncertainty lab in PHYS 211 and 212

Equipment:

Setup Instructions:

  • One person holds the top of the meter stick
  • The second person holds their hand over the 50cm mark, not touching the meter stick, ready go catch
  • Without warning, the first person lets go, and the second tries to catch it.

Apparatus Notes:

Alternatively, a $20 bill may be used instead. This version does not measure reaction time, only shows that it is unlikely that someone can react fast enough to catch it.
It does have the benefit of being more interesting to students, but be prepared to lose the money if a student can read your body language.

Safety Information: None.
Location: Demo Rm Shelf U
JHA