## anonymous 4 years ago Please help! A ball is dropped from the top of a 1,000 foot building. The height of the ball is half its original height after each bounce. What will the height of the ball be after 12 bounces? Using complete sentences, explain the procedure taken to answer this question.

1. anonymous

You dont have explain in sentences. I just want the height please!

2. anonymous

This is geometric sequence

3. anonymous

Yes it is, I get the answer 0.48828125, But i dont think it is right.

4. anonymous

a = 1000 r = 1/2 n = 12 $1000 (\frac{1}{2})^{n-1}$

5. anonymous

It should be n not n-1

6. anonymous

Ok I did that and get 0.488281125

7. anonymous

$1000 (\frac{1}{2})^{12}$

8. anonymous

But why not n-1?

9. anonymous

Because the formula I am given is with n-1, hmm idkk

10. anonymous

Do you mean the geometric formula that you are given or this question provides you a formula?

11. anonymous

Well that's the only formula I am given in my lesson.. yeah the first part of ur question is right

12. anonymous

It shouldn't be n-1. You need to visualize the situation

13. anonymous

Ok, then why don't you use -1? Because the first height wouldn't count right?

14. anonymous

|dw:1323133998962:dw|

15. anonymous

thanks, i kinda understand now.

16. anonymous

Glad that you get help from Open Study

17. anonymous

Thank you :)