# Proportional ratios with exponents - Need Help

1. Oct 15, 2012

### kathleenhelen

proportional ratios with exponents - Need Help!!

A walker's speed, v, is proportional to the ratio of his leg length, L, and the period of the repeating motion of his legs, T, that is, v ∝ L/T. If the period is measured to be proportional to Lp, where p = 4/5, what power of L must the speed be proportional to?

I have absolutely no idea how to do this problem. I've tried it a couple times and I'm getting no where with it. Please help!!! The more you could explain the answer the more helpful it would be as well!

2. Oct 15, 2012

### tiny-tim

welcome to pf!

hi kathleenhelen! welcome to pf!
that doesn't make sense

do you mean the period is measured to be proportional to L4/5 ?

3. Oct 15, 2012

### kathleenhelen

Re: proportional ratios with exponents - Need Help!!

Yes! Sorry, I mistyped the question by accident, but the 4/5 is supposed to be an exponent.

4. Oct 15, 2012

### tiny-tim

ok, v ∝ L/T means v = aL/T for some constant a

similarly T = bL4/5 for some constant b

so v = … ?