Question

The average human is able to jump vertically with an initial speed of 8.5 ft/s. What is the hang time of such a jump, ignoring air resistance? Use the formula h=-16t^2+8.5t, where h is the height off the ground in feet and t is the time in seconds after the jump. Round your answer to the nearest tenth.
a) 0.2 seconds
b) 0.5 seconds
c) 0.8 seconds
d) 1.2 seconds