# Homework Help: How many photon/sec?

1. Apr 18, 2010

### phy_freak

How many photon/sec??

An FM radio transmitter has a power output of 100 kW and operates at a frequency of 97.5 MHz. How many photons per second does the transmitter emit?

2. Apr 18, 2010

### Dauden

Re: How many photon/sec??

3. Apr 18, 2010

### karkas

Re: How many photon/sec??

Ok, consider first that the power output of the transmitter is the energy released from the transmitter in a given time (in the form of photons) divided by that time, as in

$P_{ower of transmitter}=\frac{E_{nergy emitted}}{t_{ime}}$ and think of the energy as a number of photons. Where do you get?

4. Apr 20, 2010

### phy_freak

Re: How many photon/sec??

oh thanks i managed to solve it