First off, you need to know the weight of the projectile, lift and drag coefficients something like a high Reynolds number is preferred, then use the gravitational constant of 9.8 meters per second squared those would be a good start to get closer to your goal
23.5 DEGREES is the answer.
Atoms diameter are on the order of 60 to 600pm (picometers). This is around 6*10^-11.
A: the type of plant
B: how tall the plant is