QUESTION 10 Grade 12 Physical Sciences students perform an experiment using a photocell to investigate the relationship between the kinetic energy of the photoelectrons and the frequency of the incident light. UV light of frequency 9,1 x 1014Hz is shone onto silver metal. The work function of silver is 4,33 x 10-J. An electron is ejected during this experiment. 10.1 Define the term threshold frequency 10.2 Determine the threshold frequency for silver. 10.3 Red light replaces the UV light used in the experiment and is shone onto the silver. It is observed that no electrons are emitted from the surface of the metal. Explain why this occurs. 10.4 A graph of this experiment is plotted as the maximum kinetic energy against the frequency of the incident light. When a straight line graph is extrapolated (as seen on the next page), it intercepts the x-axis. 10.4.1 What value does the x-intercept represent on this graph? (1) 10.4.2 Calculate the kinetic energy at E1 shown on the graph