Hi,
I want to measure the velocity of the car
I want to feel the exact velocity also if the car is slipping or if there is a big friction and the car is deceleration
How I can do it ?
You don't really mean "to feel" it, right?
To measure it, count revolutions for a given time* of two wheels (eg. left front and back wheel) and as long as they're equal. Measuring both wheels will show slippage by a large difference in the time it takes for a revolution (or part of one).
* You measure the time for a full, half, tenth or whatever revolution and the inverse is a measure of velocity.
Maybe an accelerometer can help for this mission
A car going a steady 10, 100 or 1000 mph will have an acceleration of zero.
For this mission I want to understand how the old computer mouse and the new optical computer mouse works maybe it can help me to solve this problem
Start
here and allways remember to Google such stuff yourself before asking!