Answer:
It takes 2.8 seconds for the ball to fall 215 ft.
Step-by-step explanation:
We are given a position function s(t) where s stands for the number of feet the ball has fallen, so we have to replace s with the given value of 215 ft and solve for the time t.
Setting up the equation.
The motion equation is given by
We can replace there s = 215 ft to get
Solving for the time t.
From the previous equation we can move all terms in one side to get
At this point we can solve for t using quadratic formula.
where a, b and c are the coefficients of the quadratic equation
So we get
Replacing on the quadratic formula we get
Using a calculator we get
Physically speaking the only result that makes sense is to move forward in time that give us t = 2.8 seconds.
We can conclude that it takes 2.8 seconds for the ball to fall 215 ft.