For a baseball to travel 90 meters, with what velocity must it be hit if the angle of impact is 40°? Flight time is 3.9 seconds.

Answer 1

The x equation of motion is v₀cos(40°)t_air = range (Solve for time in the air)

You now have t_air which has the equation for a symmetric launch problem of 2v₀sin(40°)/g = t_air which allows you to solve for v₀ (This equation is derived from -v₀ = v₀ -gt_air)