Question

A projectile is launched with the velocity of 100 meters/second and at an angle 45° from horizontal. If the projectile's hang time is 14.43 seconds, what is its range?

Answer 1

Ignoring air resistance there’s no net force in the x direction once the projectile is launched, so the velocity in the x direction remains constant. The velocity vector is simply (magnitude of velocity)cos(theta). From there, velocity = displacement/time so you can then plug in the velocity and time to get the horizontal displacement (range).