
#1
Dec111, 06:04 PM

P: 3

I go rock climbing a lot with my BSA troop, and my friends and I can only estimate the height. I want to know the exact height. Considering I do not have a ruler long enough to measure the height of the cliff, I know there is a way to throw an object off the cliff (say, a rock), time how long it takes to hit the ground, and then do some math and then you have the height.
I want to know how to do the math. Please be detailed with your answer, because I'm 15 and not really a math genius (I'm good, but not THAT good). Thanks. 



#2
Dec111, 06:54 PM

Mentor
P: 21,067

t is in seconds and h is in feet. 



#3
Dec111, 07:29 PM

P: 1,227

Make sure if you use mark's equation that the rock is either dropped or thrown straight ahead.




#4
Dec111, 07:39 PM

P: 15,325

How to calculate the height of something by throwing an object off it?
BTW, there are other ways that might have less error than estimating a time of a second or two.
You can figure out how far you are from the base of the cliff and use trig to calculate its height. 



#5
Dec111, 07:48 PM

Sci Advisor
P: 779

But yes, trig is how it has always been down in the past. And we have GPS now, so it's easier too. 


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