# Electromagnetic waves [simple one]

#### cupcake

1. Homework Statement

Public television station KQED in San Francisco broadcasts a sinusoidal radio signal at a power of 316 kW. Assume that the wave spreads out uniformly into a hemisphere above the ground.

At a home 6.00 km away from the antenna, what is the average density of the energy this wave carries?

For the energy density in part (a), what percentage is due to the electric field?

For the energy density in part (a), what percentage is due to the magnetic field?

2. Homework Equations

u= P/ (c*a)

u=1/2*epsilon* E^2 + 1/2mu * B^2

3. The Attempt at a Solution
i managed to do part A, by using equation u=P/(c*a)

i dont know how to get the percentage,, please advise

Related Introductory Physics Homework Help News on Phys.org

### Want to reply to this thread?

"Electromagnetic waves [simple one]"

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving