Question

Keisha throws a rock down an old well the distance D in Feet The Rock Falls after T seconds can be represented by D =16t ^ 2 + 64t if the water in the well is 80 ft below ground how many seconds will it take for the rock to hit the water?​

Answer 1

Answer:

1 second

Step-by-step explanation:

16t^2+64t=80

16t^2+64t-80=0

64^2-4(16)(-80)

9216

-64-96

______ = -5

32

-64+96

_______ = 1 sec

32