Question

i needed help with problems 2,3 and 4! please help exam is tomorrow im going in circles with these problems

1. A 5.0-watt laser pointer emits light of 400 nm wavelength. How many photons are emi each second? Express your answer as a multiple of 1.0 x ted E-nt e (b) 4.6 e) None of these c- 5.0 xIU Would have to the frequency of light (as a multiple of 1.0 x 1015 Hz) incident on a metal function is 5.0 eV that would create photo-emitted electrons whose maximum speed ose work E: hv (G-ㄐㄨ (c) 3.5 (d) 4.8 28 2-484 379s nnte e) None of these 142.13 3. The longest wavelength of light that will cause photoemission from a certain metal is What is the maximum kinetic energy (İney) of photo-emitted electrons when light of nm. wavelength 100 nm is incident on the surface? (a) 3.4 (b) 5.1 (c) 2.5 (d) 6.5 (e) None of these 4. Imagine an alternate universe in which all the laws of physics are the same as in ours, except that the electric force law is F kQiQ2/r. On which power of the quantum index n do the quantized orbital radii depend? (a) -1/2 니 (b) -1/3 (d) -2 (e) None of these nc

Answer 1

krok fun honto-5.0eV ② mant photons g.1x103((6-Yyis) 34 ox 2150刈.byo + 21 66 l ニ - 21 31 eV ) [-6下10