- #1
Coushander
- 27
- 0
Homework Statement
A tiny vibrating source sends waves uniformly in all directions. An area of 3.25 cm2 on a sphere of radius 2.50 m centered on the source receives energy at a rate of 4.20 J/s.
(a) What is the intensity of the waves at 2.50 m from the source?
(b) What is the intensity of the waves at 10.0 m from the source?
(c) At what rate is energy leaving the vibrating source of the waves?
Homework Equations
I = Power/Area
Area (sphere) = 4(3.14)r2
The Attempt at a Solution
a) Power = 4.20 J/s
Radius = 2.5 m
Area = 4(3.14)(2.5)2= 25(pi)
I= 0.0534 W/m2
The actual value of I is 1.29x104 W/m2
If I say Area= 3.25cm2 then I get I = 129.23 W/m2