Speedometer

[Blenderite]

I was just wondering if anyone has ever used a bike speedometer to record the speed of a water rocket at launch? Also, I thought of a system that could be made so that there is a fan shaped object outside the rocket, with a bike speedometer rigged up to check maximum speed during the flight. I am not sure if that is even a good idea. Should I try to make something like this?

-DogLover

[Azriel]

I was just wondering if anyone has ever used a bike speedometer to record the speed of a water rocket at launch? Also, I thought of a system that could be made so that there is a fan shaped object outside the rocket, with a bike speedometer rigged up to check maximum speed during the flight. I am not sure if that is even a good idea. Should I try to make something like this?

-DogLover

look into pitot tubes, that's how speed is determined in aircraft.

Bicycle speedometers calculate speed by measuring the rotation and of the wheels, so they wouldn't be very suitable in a water rocket with no real moving parts

[U.S. Water Rockets]

I was just wondering if anyone has ever used a bike speedometer to record the speed of a water rocket at launch? Also, I thought of a system that could be made so that there is a fan shaped object outside the rocket, with a bike speedometer rigged up to check maximum speed during the flight. I am not sure if that is even a good idea. Should I try to make something like this?

-DogLover

The maximum speed would be right around the burnout time, so the best solution is to videotape the launch and place a scale like a long board with units of length marked off. Then you simply play back the video and divide the number of units the rocket moves between each frame by the time between frames. You now have the speed and it adds no weight or complexity to the rocket.