There are many ways to calculate force. However, they are completely different aspects. The force on an area is pressure, so F = p*A. In magnetic fields you use another formule (forgot the formule atm). Unless you define what kind of force you are looking for, I can't help you any further.
Which type needs the highest temperature to grow in?
Do all of the types make food the same way?
How long does it take for a specific type to make its seeds?
The other questions are all personal opinion
Just the First 2 listed :D
With what? maybe I can help?
This is the half life of the substance. The half life is the time it takes for the substance to become reduced by half as a consequence of decay.