Answer:
The ball is in the air for approximately 3.27 seconds ⇒ answer A
Explanation:
* Lets explain how to solve the problem
- The height of the ball is modeled by the function
h(t) = -4.9 t² + 16 t
- We need to find the time that the ball is in the air
- The ball is in the air from its initial position and then return to the
same position
- That means h(t) = 0 because h(t) represent the height of the ball
from its initial position
∵ h(t) = -4.9 t² + 16 t
∵ h(t) = 0
∴ 0 = -4.9 t² + 16 t
- Add 4.9 t² to both sides
∴ 4.9 t² = 16 t
- Subtract 16 t from both sides
∴ 4.9 t² - 16 t = 0
- Take t as a common factor
∴ t (4.9 t - 16) = 0
- Equate each factor by 0
∴ t = 0 and 4.9 t - 16 = 0
∵ 4.9 t - 16 = 0 ⇒ add 16 for both sides
∴ 4.9 t = 16
- Divide both sides by 4.9
∴ t = 3.2653
∴ t = 0 ⇒ initial position
∴ t = 3.2653 seconds ⇒ final position
* The ball is in the air for approximately 3.27 seconds