How does people measure the speed of a car?

for cars, it takes some time for it to go from 0km/h to 100km/h. If the car is manual transmission, how do people measure the time it takes to accelerate from 0km/h to 100km/h. Does a human drive the car? If so, people have different changing gears speed... how they know the time it take for the car to accelerate?How does people measure the speed of a car?
';do';



Do you mean: How do they get consistent values for performance numbers, like 0-60 time?



The drivers are very good and experienced, and take lots of practice runs. They, the drivers, know/learn the best points at which to shift to get the best performance.





.How does people measure the speed of a car?
it is a measure of distance per time



e.g. the car travels a known distance of 1760 feet in 15.0 seconds

using conversion fractions, this would equal 60 miles/hour
The correct equation is:



Velocity (or speed) = distance/time



thus



time= distance/velocity



There are also known speed ranges for optimum gear changes in a manual transmission. Good drivers know that and eventually do it by ';feel';.