# Modeling

• Apr 14th 2013, 02:48 PM
tracieemra72
I need help with Modeling
This is a word problem and I have no clue how to solve it.

Mt. Thor in Canada is said to have the longest vertical drop(4100 ft.) on Earth. How long would it take for a pebble dropped off the cliff to reach the ground? (Hint: The height of a falling object above the ground t seconds after it is dropped can be modeled by s(t) = -16t^2 + So where So is the initial height.)
• Apr 14th 2013, 02:49 PM
tracieemra72
The S is height and t is seconds.
• Apr 14th 2013, 05:20 PM
topsquark
Re: I need help with Modeling
Quote:

Originally Posted by tracieemra72
Mt. Thor in Canada is said to have the longest vertical drop(4100 ft.) on Earth. How long would it take for a pebble dropped off the cliff to reach the ground? (Hint: The height of a falling object above the ground t seconds after it is dropped can be modeled by s(t) = -16t^2 + So where So is the initial height.)

S_0 = 4100 ft, s(t) = 0

$s(t) = -16t^2 + s_0$

$s(t) - s_0 = -16t^2$

Can you finish from here?

-Dan
• Apr 14th 2013, 06:19 PM
tracieemra72
Re: Modeling
thanks Dan. I have no clue where to go from here. When I entered it in my calculator I came up with S(16)=4 S= 16 secs. with 4 being the So? I have to find out how many seconds it would take for the pebble to be dropped from 4100 ft to hit the ground. I have never done a problem like this nor do I know how to figure it out.
• Apr 14th 2013, 07:03 PM
topsquark
Re: I need help with Modeling
Quote:

Originally Posted by topsquark
S_0 = 4100 ft, s(t) = 0

$s(t) = -16t^2 + s_0$

$s(t) - s_0 = -16t^2$

Plug the numbers in:
$0 - 4100 = -16t^2$

$\frac{4100}{16} = t^2$

Surely you can finish it now?

-Dan