$2\mathrm{.}9($Physics: acceleration$)$ Average acceleration is defined as the change of velocity divided by the

time taken to make the change, as given by the following formula:

$a=\frac{v_1-v_0}{t}$

Write a program that prompts the user to enter the starting velocity $v_0$ in meters$/$second$,$ the ending

velocity $\frac{v}{?}$ in meters$/$second$,$ and the time span $t$ in seconds, then displays the average acceleration.