Question 20 (1 point) You are observer A and you are holding clock A. Observer B passes you, holding clock B and moving at 0.90c. Select the best statement from the options below O Both the first and second are true You see clock A running normally and clock B running slowly O You see clock B running slowly, and observer B sees clock A running faster than normal Observer B sees clock B and A running slowlyQuestion 17 (1 point) Which of the following best demonstrates how a light ray will refract in the situation represented in the drawing? n = 1.0003 n = 1.35 n = 1.0003 n = 1.35 O n = 1.0003Question 18 (1 point) Using the figure below answer the following . Which statement is true? air nair = 1.00 soap film nfilm = 1.35 glass glass = 1.52 a phase change occurs at both boundaries a phase change occurs at the top boundary only a phase change occurs at the bottom boundary only a phase change does not occurQuestion 19 (1 point) Light with a wavelength of 411 nm is represented in the following diagram incident light ray 2 ray 1 ray 3 air nair = 1.00 oil film nfilm = 1.41 glass nglass = 1.52 (transmitted ray) Figure 1 What is the minimum thickness of the soap film in order to see the light? 7.62 x 10-8 m 1.52 x 10-7 m 1.46 x 10-7 m 7.62 x 10-7 mO n = 1.0003 n = 1.35 n = 1.0003 n = 1.35Question 16 (1 point) What is the frequency of a wave that has a wavelength of 0.550 m and is travelling at 755 m/s? 1985 Hz 1370 Hz 415 Hz 0.000728 Hz