To the Editor,
Your September 18 article “Heidelberg man fears speed cameras a cash grab” raised some interesting physics questions.
So, a friend and I, and our reliable 2007 Honda minivan, visited St. Clements on a quiet Sunday night to answer a few of these questions. Can a car accelerate to 51km/h in the 90 metres from the corner before the speed cameras? Would someone have to accelerate recklessly to do so?
Before we tell you the answers, we uncovered some other interesting data. The warning sign is indeed 90m from the corner, however, the speed cameras are targeted at a spot further 32m for a total distance of 122m. We assumed the lesser distance of 90m for our experiments.
The answer – the Honda minivan reached 64kph at the 90m distance, while accelerating moderately.
Other vehicles available to us showed the following maximum speeds in 90m distance. (Note, these experiments were done elsewhere.) Ford F150 – 113 km/h; (very fast) EV – 129 km/h.
A quick check shows that only three production vehicles since 1950 would not be able to reach 51 km/h in 90m, all because of maximum speeds lower than 50.
So thanks to physics, we know that, yes, a “cautious driver” like Mr. Sinclair could indeed easily reach 51 km/h before the speed camera.
Mark Schwarz (victim of many a speed trap)
Floradale
