## June 01, 2009

### Maths Challenge #7 – How Deep is the Well?

I drop a rock down a well, and it takes 6s to reach the bottom. If gravity is 10m/s², how deep is the well?

### 5 comments by 1 or more people

1. #### Daniel Corne

30? Assuming it starts from rest…

01 Jun 2009, 12:02

2. #### Simon Whitehouse

180m Using Newton’s Third Equation of Motion and u=0 you end up with s=1/2*10*6^2=180

01 Jun 2009, 12:34

3. #### Daniel Corne

Woops forgot the power of two… =/

01 Jun 2009, 16:09

4. #### Eleanor Lovell

There were a few mixed answers to this one but the actual answer is 180m.

The formula needed to find out the depth is one of Newton’s laws of motion…

$s = \frac{1}{2}g{t^2}$

So…

$s = \frac{1}{2}g{t^2} = \frac{1}{2} 10{(6)^2}$ = 180 metres

02 Jun 2009, 12:37

5. #### free textures

Far too smart for me!

03 Jun 2009, 13:24

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Warwick Challenges are mini academic challenges from University of Warwick professors, set via the micro-blogging service Twitter (and also via this blog).
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