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

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

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

∴ The new near point is 17.4 cm