Raymond B. answered 02/18/21
Math, microeconomics or criminal justice
h(t) = 84 -16t^2
at initial time t=0, the ball is at height 84 with initial velocity=0. It's not tossed upwards with this equation. It's dropped, but without being tossed downward either.
it reaches a maximum height when h'(t) = 0 = -16t, at time t=0, at height = 84, after that it goes down to lower heights.
It reaches ground level, h=0, when 16t^2 = 84 feet
t^2 = 84/16 = 42/8 =21/4
t = sqr(21/4) = (1/2)sqr21 = about 2.3 seconds, the time it takes gravity to pull the ball 84 feet down
the term -16t^2 indicates deceleration due to gravity at 32 feet per second per second
You need a t term if the ball was tossed upwards with any velocity > 0. Vot is missing where the coefficient of a linear t term is the initial velocity. With just 84-t^2, initial velocity is zero