Turn over 5 7 The photoelectric effect provides evidence for the particle nature of electromagnetic radiation. Which of the following observations of the photoelectric effect could also be explained using the wave nature of electromagnetic radiation? A The emission of photoelectrons is instantaneous. B The maximum kinetic energy of photoelectrons depends on frequency. C The rate of emission of photoelectrons depends on intensity. D There is a minimum frequency for emission of photoelectrons to occur. (Total for Question 7 = 1 mark) 8 The acceleration of free fall at the surface of the Earth is 9.81 m s−2. The mass of the Earth is M and the diameter of the Earth is D. Which of the following gives the acceleration of free fall, in m s−2, at the surface of a planet with diameter D 2 and mass M 9 ? A 9 81 2 9 . × B 9 81 4 9 . × C 9 81 2 3 . × D 9 81 9 4 . × (Total for Question 8 = 1 mark)