Complete question:
How many x-ray photons per second are created by an x-ray tube that produces a flux of x rays having a power of 1.00 W. Assume the average energy per photon in 78.0 keV.
Answer:
The number of x-ray photons per second created by the x-ray tube is 8.01 x 10¹³ photons/sec
Explanation:
Given;
power of the flux produced, P = 1 W = 1 J/s
energy per photon, E = 78 keV
Convert the energy per photon to J
E = 78 x 10³ x 1.6 x 10⁻¹⁹ = 1.248 x 10⁻¹⁴ J / photon
let the number of photons = n
n(1.248 x 10⁻¹⁴ J / photon) = 1 J/s
![n = \frac{1 \ J/s}{1.248 \times 10^{-14}\ J/photon } = 8.01 \times 10^{13} \ photons/s](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B1%20%5C%20J%2Fs%7D%7B1.248%20%5Ctimes%2010%5E%7B-14%7D%5C%20%20J%2Fphoton%20%7D%20%3D%208.01%20%5Ctimes%2010%5E%7B13%7D%20%5C%20photons%2Fs)
Therefore, the number of x-ray photons per second created by the x-ray tube is 8.01 x 10¹³ photons/sec
I need to see the picture. It is either gravity or air resistance (friction)
Solar energy or sunlight...
Answer:
17.4 cm
Explanation:
Power of lens = +1.75 diopters
Focal length of lens
![f=\frac{100}{1.75}=\frac{400}{7}](https://tex.z-dn.net/?f=f%3D%5Cfrac%7B100%7D%7B1.75%7D%3D%5Cfrac%7B400%7D%7B7%7D)
This is a convex lens as focal the diopter given is positive which makes the focal length positive. Image distance will be negative.
v = -25
![\frac{1}{v}-\frac{1}{u}=\frac{1}{f}\\\Rightarrow \frac{1}{-25}-\frac{1}{u}=\frac{1}{\frac{400}{7}}\\\Rightarrow -\frac{1}{u}=\frac{7}{400}+\frac{1}{25}\\\Rightarrow \frac{1}{u}=-\frac{7}{400}-\frac{1}{25}\\\Rightarrow \frac{1}{u}=-0.0575\\\Rightarrow u=-17.4\ cm](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bv%7D-%5Cfrac%7B1%7D%7Bu%7D%3D%5Cfrac%7B1%7D%7Bf%7D%5C%5C%5CRightarrow%20%5Cfrac%7B1%7D%7B-25%7D-%5Cfrac%7B1%7D%7Bu%7D%3D%5Cfrac%7B1%7D%7B%5Cfrac%7B400%7D%7B7%7D%7D%5C%5C%5CRightarrow%20-%5Cfrac%7B1%7D%7Bu%7D%3D%5Cfrac%7B7%7D%7B400%7D%2B%5Cfrac%7B1%7D%7B25%7D%5C%5C%5CRightarrow%20%5Cfrac%7B1%7D%7Bu%7D%3D-%5Cfrac%7B7%7D%7B400%7D-%5Cfrac%7B1%7D%7B25%7D%5C%5C%5CRightarrow%20%5Cfrac%7B1%7D%7Bu%7D%3D-0.0575%5C%5C%5CRightarrow%20u%3D-17.4%5C%20cm)
∴ The new near point is 17.4 cm