A couple of weeks ago I blogged about the Hot Wheels Radar Gun. When I looked through my traffic for the last week (using Google Analytics) I saw "Hot Wheels Radar Gun" pop up as the most common search terms leading readers to my blog. So I decided I should probably conclude my testing to determine if it works.
After my last installment I had the feeling that it worked for constant velocity. I have confirmed that it works surprisingly well. I still need to experiment with accelerating objects though.
Experiment #3: Velocity of a constant velocity car
I experimentally determined the speed of my constant velocity car by timing it over a distance of two meters. I arrived at an average velocity of 0.157 m/s after three trials. With the radar gun set to scale speed (1/64) and kph I was able to get a reading of 35. Every time I did it I got 35 exactly. This converts to an actual speed of 0.15 m/s. If I use the 0.157 as the expected value I arrive at a percent error of 4.5%. I think that's Great!!!
Experiment #4: Real Velocity
Fresh off the constant velocity car I decided to try a real car. So I drove around the empty parking lot at my school and shot the light posts as I went by. I got the same reading as my speedometer every time.
The Hot Wheels Radar Gun works!!! At least for relatively constant velocity objects. I still need to determine how accurately it will measure velocity on an accelerating body.
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