can someone explain this to me?

4. Monochromatic light of wavelength 500 nm falls on a metal cathode to produce photoelectrons. The intensity of the light at the metal surface is 100 Joules/mZ/s. a. What is the energy of a single photon of this light? b. How many photons fall on one square meter in one second? EQUATIONS Kinematics Waves Atomic Physics Vave = Ad d = vit - sat hi T = 27N m = = -di W = hfo E = hf =! hc At do AV Ek axle stop N = No() dave = d = Vetvit 2 T = 20Ng = do + di d = vit + zat ve = v.+ 2ad n2 sine T = 7 Quantum Mechanics and Nuclear Physics sin 62 AE = Amc2 E = pc T2 n2 VI 21 v = fa = V2 P = Dynamics h (1 - cose) Al = mc( Fnet Gm m2 a = m F. = f = (viv)fs a = d sine n Trigonometry and Geometry 8 = Gm opposite Line 1 = sin0 = hypotenuse Ay nl m = - Ax F = -kx F g g = m adjacent cos0 = y = mx + b Electricity and Magnetism hypotenuse Momentum and Energy kq 192 AV = AE tan0 = opposite Area Fe = adjacent p = mv Ek = mv2 12 Rectangle = /w E = 12 c2 = a2+62 F At = may Ep = mgh 1 = 4 Triangle = Tab W = |Fl la |cose Circle = mr- Ep = 5kx2 Fe a b |Fm| = 11 B| sin A sin B = E = q sin C W = AE Circumference E = AV |Fm| = qVB| c2 = a2 +62 - 2ab cos C Circle = 2ar P = W AdPHYSICS DATA SHEET Constants Prefixes Used with SI Units Particles Acceleration Due to Gravity Exponential Charge Mass Near Earth....... ......". dig| =9.81 m/s2 Prefix Symbol Value Gravitational Constant ...... G =6.67 x 10- N-m2/kg2 Alpha Particle.... . +2e atto . 10-18 6.65 x 10-27 kg Radius of Earth ..... ............". /2 = 6.37 x 10 m femto ....... f..............10-15 Electron .... ....... -le 9.11 x 10 kg Mass of Earth... ............... Me = 5.97 x 1024 kg pico......... P......... 10-12 Proton ...... ......... +le 1.67 x 10 2 kg Elementary Charge ........... e = 1.60 x 10-19 C nano.. . .... n........... 10-9 Coulomb's Law Constant .. k = 8.99 x 109 N.m-/C2 micro ...... H ............ 10-6 Neutron........ 0 1.67 x 10-27 kg Electron Volt ... ......... leV = 1.60 x 10-19 J milli.......... m............. 10-3 First-Generation Fermions Index of Refraction of Air. n = 1.00 centi...... C.............. ....10-2 Charge Mass Speed of Light in Vacuum. c = 3.00 x 10 m/s deci..... d......10-1 Electron ... .......-le ~0.511 MeV/c2 Planck's Constant ....... h = 6.63 x 10-34 J.s deka .......... da..... I 101 h =4.14 x 10 eV.s Positron ... ~0.511 MeV/c2 hecto ... h.... 102 ......... +le Atomic Mass Unit .......... u = 1.66 x 102 kg kilo ..... K........103 Electron neutrino, V... 0