Michael jordan was said to have a hang-time of 3.0 seconds. use kinematic equations to determine the height to which he could leap

The hang time is 3 seconds, which is the time of travel off the ground.
The maximum height is attained in 3/2 = 1.5 s.

Acceleration due to gravity  = 9.8 m/s
Wind resistance is ignored.

At maximum height, the vertical velocity is zero.
If u is the vertical launch velocity, then
(u m/s) - (9.8 m/s²)*(1.5 s) = 0
u = 14.7 m/s

The maximum height is
h = (14.7 m/s)*(1.5 s) - 0.5*(9.8 m/s²)*(1.5 s)²
   =11.025 m

11.0 m (nearest tenth)