A local FM radio station broadcasts at an energy of 6.24×10-29 kJ/photon. Calculate the frequency at which it is broadcasting. Frequency = MHz (1 MHz = 106 sec -1)

Answer 1

I agree with J.R. S. above. That is exactly how I would do it.

I would also point out that 6.626x10^-34 J-sec is Planck's constant, h, in case anyone was confused by that.

So the formula E=hν becomes 6.24x10^-29 kJ = 6.626x10^-34 J-sec * ν

Then just convert the 6.24x10^-29 kJ to Joules by multiplying by 1000 J/kJ and divide by 6.626x10^-34 J-sec to get the answer in 1/sec, which is Hz.

Then multiply by 1 MHz / 1x10⁶ Hz to get the final answer in MHz.

Answer 2

You are given the energy of a photon = 6.24x10^-29 kJ

You are asked to find the frequency (ν),

We use the equation E = hν where E is energy, h is Planck's constant and ν is the frequency

6.24x10^-29 kJ = 6.626x10^-34 J-sec * ν

ν = 6.24x10^-29 kJ x 1000 J/kJ / 6.626x10^-34 Jsec

ν = 6.24x10^-26 J / 6.626x10^-34 Jsec

ν = 0.942x10⁸ s^-1 = 9.42x10⁷ s^-1 = 9.42x107 Hz

9.42x10⁷ Hz x 1 MHz/10⁶ Hz = 94.2 MHz