How can I use a speedometer to measure acceleration?

Other Hardware Sensors
1

I just bought a Reed Switch with a magnet to measure a wheel's rotation per minute. I'm using an arduino to convert the rotations/minute to miles per hour for a wheel.

Any way we can store the rotation data to measure acceleration, also?

For example, if the rotations/min start increasing over a 10 second span, I'd like the output to be something else.

Would love to see if anyone knows!

2

By definition, acceleration = (change in speed)/(time to change)

3

also written as A = dV/dT

4

My laser tachometer only gives a reading every 0.9s, but capturing 100fps video of laser tachometer and capturing microsecond resolution timestamps allows to determine even extreme acceleration -- I just determeined 12.18g accelecation ("from 0 to 394km/h in 0.92s"):
https://forum.arduino.cc/index.php?topic=636736.msg4320009#msg4320009