[单选题]
16.21: At 1.94 s after launch, a projectile in free fall a;-iclrn)/ qdw cli*v 1p5y.0 ed1xgvb ihieved its minimum speed during flight. If that minimg el*xv vy 1bi0p.i1d5um speed was 15.0 m/s, what was the projectile’s initial angle of launch from the horizontal?
