Question

A car goes from 40 m/s to 30 m/s in 5 sec. What is its acceleration?

Please help me

Answer 1

The car's average acceleration is

a (ave) = (30 m/s - 40 m/s)/(5 s) = -2 m/s^2

(That is, divide the change in velocity by the time it takes for the change to take place.)

If acceleration is constant, then it is equal to the average acceleration.