Ok, please dont laugh, but i am sitting on a physical/mathematical problem i am unable to solve atm (blackout..).

I have a distance (300m) a V0 (0m/s) and a time (60s).

How do i calculate the mean acceleration to reach the 300m in time?

The formula is - if i am not totally wrong - " a = v(t^2)+V0" - but i simply hang myself because of the velocity in the middle part of the term...

Damn, it's been to much time since i was having physics last time, or math..