150MPH converts to 67m/s.
If he is falling at a constant speed of 150MPH, then he is not accelerating.
As he is not accelerating, the net force = gravity force - wind resistance = 0
wind resistance = gravity force
= 90(9.8) = 882N
If there is no wind resistance, by conservation of energy,
final Kinetic Energy = initial Potential energy
= mass * gravity * height
= 90*9.81*7620
= 6720840J
He is unhurt because the safety net provides a soft landing. It decelerates his momentum gradually over time to avoid injury.