Answer:
2 seconds
Explanation:
Given
h = - 32t² + 64t
When the frisbee lands the height h = 0, that is
- 32t² + 64t = 0 ( multiply through by - 1 )
32t² - 64t = 0 ← factor out 32t from each term
32t(t - 2) = 0
Equate each factor to zero and solve for t
32t = 0 ⇒ t = 0
t - 2 = 0 ⇒ t = 2
t = 0 represents when the frisbee was thrown
and t = 2 when it lands
Hence it takes 2 seconds for the frisbee to land.