Question

What is the average velocity of a dragster that starts from rest at the starting line and finishes a race at 2600 m/s in 12 seconds?

Answer 1

Using the equation v(avg)=distance/time 
and the equation v=v(original)+a(t)
solve for acceleration
2600=0+a(12)
a=216.66666 m/s^2

Then, you use the equation
v^2=v(original)+2a*(change in x)
2600^2=2(216.666666)*change in x
6760000/2/216.666666 = 15600 meters which is the length of the race

Then using v(avg)=x/t
15600/12= 1300 m/s