When blue light (450 nm) is shone on a particular metal surface, electrons are ejected within a kinetic energy of 2.5 x 10^-20J.

a. Calculate the work function for this metal.
b. Will green light (500 nm) cause an electron to be ejected?
c. What is the longest wavelength light that will eject an electron?

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?