1. A point on the third nodal line from the center of an interference pattern is 35 cm from one source and 42 cm from the second source. The sources are 11.2 cm apart and vibrate in phase at 10.5 Hz. (6 marks) (a) Calculate the wavelength of the waves. (b) Calculate the speed of the waves. 2. A student shines a red laser at two slits in a piece of paper. The slits are 0.080 mm apart. A screen is placed 2.0 m away from the slits. (a) Clearly explain why a pattern of bright and dark fringes is visible on the screen. (4 marks) (b) Upon taking measurements, the student determines that there are 5.0 cm between the first and fourth nodal lines. the distance from the centre of the pattern to the third nodal line is 4.2 cm. the angle to the eighth anti-nodal line from the right bisector is 3.8. Perform three different calculations to determine the wavelength of this light. Account for any difference in values. (6 marks) 3. The student in Questions 1. wants to make some adjustments to the experiment to have fringes that are closer together. Refer to the appropriate equation(s) to predict three different ways that the experiment could be changed to have closer fringes. (6 marks)