Getting the Speed of a car

I want to get the speed of a car. What are the ways of doing it?

Depends on whether you're in/on the car or not

It doesn't matter as long as i can get the speed

kevinnths: It doesn't matter as long as i can get the speed

Well, if you're not in or on the car, GPS (for example) isn't going to be much use, so I'd say, yes, it does matter.

If you're not in the car the speedometer is not much use either. I suppose a transmitting video camera pointed at the dashboard would work.

Lets say that im inside the car. is GPS still good? or using a speed sensor

What’s a “speed sensor”?

Yes, in a car (assuming you’re not in a tunnel or covered car park) GPS is probably OK.

I want to get the speed of a car. What are the ways of doing it?

Looking at the speedometer is fairly typical.

Wait until the end of year, and count up the speeding tickets

kevinnths: It doesn't matter as long as i can get the speed

Then set up two sensors of some type a few meters apart along the path the car will take and see how long it takes the car to go between them.