Explanation:
u=166m/s, v=0(at it's highest point final velocity is zero), a=9.8m/s², t=8.6s
by the formula, S=ut+½at².
S=[166×8.6+½.×9.8×(8.6)²]. ...by calculation
S = 1427.6+362.404
S=1790.004m
hope this helps you.
A
method of procedure that has characterized natural science since the
17th century, consisting in systematic observation, measurement, and
experiment, and the formulation, testing, and modification of
hypotheses
First we gotta use an equation of motion:

Our vertical distance d= 100 m, initial vertical speed u = 0 m/s (because velocity is fully horizontal), and vertical acceleration a = 9.8 m/s2 because of gravity. Let's plug it all in!

Now we just need to solve for t:

Hit the calculators, and you'll get 4.5 seconds!
Umm what are you trying to say