The function models the height y in feet of a stone t seconds after it is dropped from the edge of a vertical cliff.
y= -16t^2 + 486

How long will it take the stone to hit the ground? Round to the nearest hundredth of a second.
A. 7.79 seconds
B. 11.02 seconds
C. 0.25 seconds
D. 5.51 seconds

Question

The function models the height y in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. 
y= -16t^2 + 486

How long will it take the stone to hit the ground? Round to the nearest hundredth of a second.
A.	7.79 seconds	
B.	11.02 seconds	
C.	0.25 seconds	
D.	5.51 seconds

anonymous · Answer

At t=0 the stone is 486 feet above the ground. so at what height do you think is the ground at?

jdoe0001 · Answer

http://openstudy.com/study#/updates/543da8dee4b0f21fc543dc61

anonymous · Answer

0
yea i know how to set it up, i got confused when solving it

jdoe0001 · Answer

well. you're expected to know how to solve quadratics, thus the exercise