1. The problem statement, all variables and given/known data When a monochromatic light with a wavelength of 254 nm falls onto the surface of a particular metal it causes a photocurrent to flow. A stopping voltage of 2.30 V is required to completely block the photocurrent. What is the work function of the material? 2. Relevant equations KE = hf - Wo hf = hc/wavelength 3. The attempt at a solution I keep getting a negative number which is an impossible answer for a work function. Any help would be greatly appreciated. Thank you.