physics
posted by kayla .
An airport has runways only 142 m long. Asmall plane must reach a ground speed of 45 m/s before it can become airborne. What average acceleration must the plane’s engines provide if it is to take off safely from its airport?Answer in units of m/s2.

Vf^2=Vi^2+2ad solve for a

i do not understand that formula bob
i got 0.317 what do you get cause mine is wrong 
Vf=45
Vi=0
d=142
45^2=2*a*142
solve for a.
Yep, yours is way wrong.