Homework Help: Power and Speed

1. Feb 28, 2010

reallydumb

1. The problem statement, all variables and given/known data
Every 2km power is reduced by half. Initial power = 10watt. What is power after travelled 8km?

C = 3x108. What is speed of light passing through optic fibre? n = 1.55

2. Relevant equations

P = $$\frac{w}{T}$$ ?

3. The attempt at a solution
I dont know where to start

Last edited: Mar 1, 2010
2. Feb 28, 2010

ƒ(x)

Write a formula relating power and distance..................

P = 10(2-km/2)