Stuntman jumping off of a 20-m-high building is modeled by the equation h=20-5t^2, where t is time in seconds. A high speed camera is ready to film him between 15m and 10m above the ground. Which interval of time should the camera film him?

The answer for this question is T=2

For 10 meters we have:

h = 20-5t ^ 2

10 = 20-5t ^ 2

10-20 = - 5t ^ 2

5t ^ 2 = 10

t = root (10/5)

t = root (2)

For 15 meters we have:

h = 20-5t ^ 2

15 = 20-5t ^ 2

15-20 = - 5t ^ 2

5t ^ 2 = 5

t = root (5/5)

t = root (1)

t = 1

The time interval is:

t = [1, root (2) ]

Answer:

The interval of time that should the camera film him is:

t = [1, root (2) ] s