# Testing a proportional relationship without a graph

1. Mar 26, 2013

### GandhiReborn

1. The problem statement, all variables and given/known data

Without a graph, test the suggestion that the speed, c, of the water wave is related to water depth, d, by:

c ∝ d^1/2

No other data is given, this is suppose to be collected by myself but I am revising for a practical exam paper without having the data given. Markscheme just says "suitable data evaluated twice; correct calc.s from correct depths; appropriate concl. drawn)
2. Relevant equations

As above

3. The attempt at a solution

Surely it's simply if c ∝ d^1/2, ∴ c=kd^1/2
∴ k = c/(d^1/2)

and then I'd use collected data to find k?

Can you please just say yes, or no and help me with what I have done?

Thank you very much!!! :D

2. Mar 26, 2013

### technician

I think you are on the right track.
If you think about it you are actually calculating the gradient of a graph IF you did decide to plot a graph.
Can you see what graph you would plot IF you had been asked for a graphical method?

3. Mar 26, 2013

### GandhiReborn

Thank you. :) Yeah I'm pretty sure it'd be c against d^1/2, which if proportional should be a straight line through the origin right?