In a photoelectric experiment, light is incident on a metal surfact. Photoelectrons are ejected, producing a current. A reverse potantial is applied and adjusted until the current drops to 0 (this is called the stopping potential). This fata is collected for stopping potentials (listed first) for four different frequencies (listed second): [typo volts that reads 0,] and 2E14Hz; 0.9V and 4E14Hz; 2V and 7E14Hz; 3V and 9.3E14Hz. Determine an experimental value for Planck's constant. What is the work function of the metal? ---------- Can someone tell me what formulas to use?