Questions 4, ,5 and 6 please! Short explanation .

SES4U Grade 12 Earth & Space - University Unit: Astronomy Reference: A. Larson (U. Washington) Parallax Analysis 01. Describe the way the pencil moved against background objects when it was in the middle of the meter stick 02. Quantify (use numbers!) the change in parallax when pencil was nearer: 03. Quantify the change in parallax when pencil was farther: 04. Imagine the pencil now moving farther and farther away. Express your thoughts as to the usefulness of parallax of an object? as the distance increases. Would you theorize that there would be a limit to the usefulness of measuring the parallax 05. How does the previous question relate to our measurements of the parallaxes of stars? 06. a) You read about the geocentric model for the universe in the introduction to this exercise. Can the ignorance of the ancient astronomers be excused? Let's do a bit of calculating and comparing. The radius of the Earth is about 6400 km. The radius of the Earth's orbit is on average 150 million km. Use the radius of the Earth's orbit and the distance to the nearest star (Proxima Centauri) to determine the parallax that would be observed for this star. Use 4.2 light years as the distance of this star. [1 light year is approximately 9.5 trillion km (9.5 x 10" km)]. Use right- angled trigonometry and a labeled diagram to determine the observable parallax to determine your answer b) What is your verdict for those ancients (Ptolemy), why was no parallax being observed at that time even though it can be observed today? Give your reason! (Show and explain all logic here.) Huntsville High School R. Smith