Answer:
t = 4 seconds
Explanation:
Given that,
The height of the tennis ball above the ground can be found using the function y = -12.5x + 50
where x is the time in seconds the tennis ball has been in the air.
We need to find how many seconds did it take the tennis ball to reach the ground.
When it reaches the ground, y = 0
So,
-12.5x + 50 = 0
12.5x = 50
x = 4 seconds
So, it will take 4 seconds for the ball to reach the ground.