How many x-ray photons are emitted per second by an x-ray tube that puts out 1.0 W of 75-KeV x rays?
To calculate the number of X-ray photons emitted per second by an X-ray tube, we can use the energy of the X-ray photons and the power of the X-ray tube.
The energy of each X-ray photon can be calculated using the equation E = hf, where E is the energy, h is Planck's constant (6.626 x 10^-34 J.s), and f is the frequency. Since X-rays are a form of electromagnetic radiation, their frequency can be calculated using the equation f = c/λ, where c is the speed of light (3.00 x 10^8 m/s) and λ is the wavelength.
Given that the X-rays have an energy of 75 KeV (75 x 10^3 eV), we can convert it to joules by using the conversion factor 1 eV = 1.602 x 10^-19 J. Thus, the energy of each X-ray photon is E = 75 x 10^3 x 1.602 x 10^-19 J.
Next, we need to calculate the number of photons emitted per second (N) by dividing the power (P) of the X-ray tube by the energy of each photon (E). The power is given as 1.0 W.
Now we can proceed with the calculations:
Step 1: Convert the energy from eV to J:
E = 75 x 10^3 x 1.602 x 10^-19 J
Step 2: Calculate the number of photons emitted per second:
N = P/E = 1.0 J/s / (75 x 10^3 x 1.602 x 10^-19 J)
Calculating N will provide the desired result, which represents the number of X-ray photons emitted per second by the X-ray tube.