Projectile motion?

Question

At what minimum speed must a projectile be launched from Greenwood High to score a direct hit on Warren High. distance = 10.64 miles

Answer 1

The max range is when it is launched at 45 degrees
10.64 mi=vi*cos(45)*t
and
t=2*vi*sin(45)/g
therefore
10.64 mi=vi^2*/g
convert the miles to feet and solve for vi

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