A rock falls from a cliff 125 meters above the ground.
The equation h=125-5t(^2) represents the height (h) of the rock after (t) seconds.
How many seconds does it take for the rock to land on the ground?

Question

A rock falls from a cliff  125 meters above the ground. 
The equation h=125-5t(^2) represents the height (h) of the rock after (t) seconds. 
How many seconds does it take for the rock to land on the ground?

anonymous · Answer

is it approximately 0.45??

anonymous · Answer

I forgot my Algebra 2 years ago after I completed the class. :p Maybe someone else can run the problem and check the answer?

anonymous · Answer

lol...ohkeyy!

anonymous · Answer

We are putting h=0, right?

anonymous · Answer

no...bt it will get o...as 125-125

anonymous · Answer

h=0, as the distance is measure from the ground, so once it reaches the ground h=0 
thus 0 = 125 -5t^2
t^2=25
t=5

anonymous · Answer

plus/minus 5 but the minus figure doesn't have any meaning here...

anonymous · Answer

Clarifying; it will take 5 seconds for it to come to the ground? Or the original .45

anonymous · Answer

The equation h=125-5t(^2) represents the height (h) of the rock after (t) seconds.

anonymous · Answer

i guess majority is winning here...though m nt convinced

anonymous · Answer

Ok, so 5. Thanks guy :3