4. [-/6 Points] DETAILS MY NOTES SERPSE10 39.1.P.007. ASK YOUR TEACHER PRACTICE ANOTHER This problem is about how strongly matter is coupled to radiation, the subject with which quantum mechanics began. For a simple model, consider a solid iron sphere 1.95 cm in radius. Assume its temperature is always uniform throughout its volume. (_a) Find th_._e mass of the sphere, J g (b) Assume the sphere is at 18.5C and has emissivity 0.730. Find the power with which it radiates electromagnetic waves, | W (c) If it were alone in the Universe, at what rate would the sphere's temperature be changing? | @ | |C/s (d) Assume Wien's law describes the sphere. Find the wavelength Amax of electromagnetic radiation it emits most strongly. Although it emits a spectrum of waves having all different wavelengths, assume its power output is carried by photons of wavelength .lmax. (o (e) Find the energy of one photon. 13 (f) Find the number of photons it emits each second. . _\" photons/s Need Help? Submit Answer 5. [-/3 Points] DETAILS MY NOTES SERPSE10 39.1.P.009. ASK YOUR TEACHER PRACTICE ANOTHER A pulsed ruby laser emits light at 694.3 nm. Consider a 18.5 ps pulse containing 3.40 ] of energy. (a) Find the physical length of the pulse as it travels through space. | mm (b) Find the number of photons in the pulse. | (c) Assuming that the beam has a circular cross-section of 0.600 cm diameter, find the density of photons. ( 'i ,fmm3 Need Help? Submit Answer 6. [-/2 Points] DETAILS MY NOTES SERPSE10 39.2.0P.008. ASK YOUR TEACHER PRACTICE ANOTHER When light from a mercury lamp (4 = 546.1 nm) is incident on a particular metal surface, the stopping potential is 0.926 V. (a) What is the work function (in eV) for this metal? eV (b) What stopping potential (in V) would be observed when using light from a red lamp (41 = 650.0 nm)? L Need Help? (SRR Submit