Question

Question #841cf

Answer 1

Change in velocity is called acceleration. To calculate the acceleration of an object over a given time interval you can measure the initial velocity (`v_i`) at some time and then the final velocity (`v_f`) some time later. In the equation below the initial time is noted as `t_i` and the final time as `t_f`.
`a = (v_f-v_i)/(t_f-t_i)`

If a car accelerates from rest to 32 m/s in 4 seconds, you can calculate the acceleration to be:
`a = (32 - 0)/(4-0) = 8 (m)/(s^2)`

If you know a little calculus, the instantaneous velocity is simply the derivative of the velocity with respect to time. This is also the second derivative of the position vs. time.