Answer:
part 1) 0.78 seconds
part 2) 1.74 seconds
Step-by-step explanation:
step 1
At about what time did the ball reach the maximum?
Let
h ----> the height of a ball in feet
t ---> the time in seconds
we have
This is a vertical parabola open downward (the leading coefficient is negative)
The vertex represent a maximum
so
The x-coordinate of the vertex represent the time when the ball reach the maximum
Find the vertex
Convert the equation in vertex form
Factor -16
Complete the square
Rewrite as perfect squares
The vertex is the point
therefore
The time when the ball reach the maximum is 25/32 sec or 0.78 sec
step 2
At about what time did the ball reach the minimum?
we know that
The ball reach the minimum when the the ball reach the ground (h=0)
For h=0
square root both sides
the positive value is