- 22 Aug 2013 [11:06]
- GCR=43.9s (midnight last night was 43.8s) - looking good. Note that speed change due to diameter change on second layer is sqrt(140mm/135mm) = 1.019 (first layer diameter = 135mm, wire diameter = 5mm, drag goes as speed squared) so we expect perhaps GCR=44.7s later on as the weights descend. Air density effects, summer vs winter, max density on a dry cold day is 1.27 and min density on a hot humid day 1.14 is see [link] so the range is sqrt(1.27/1.14)=1.055 and that is about a 2.4s range from extremes.

#### Download data