Question 7 2 pts In the experiment, you will study an oscillator called a \"torsion pendulum." In this case, the restoring "force\" is the torsion constant of the wire that suspends the weight X and the inertial term is the rotational inertia of the suspended mass. You will compare the periods of a suspended sphere and of a suspended cube. The rotational inertia of a sphere is Is = 1/10 mSDZ, where m, is the mass of the sphere and D is its diameter' The rotational inertia of a cube is IC = 1/6 mCSZ, where mC is the mass of the cube and S is the length of its side. If the cube and the sphere are suspended from the same wire, what is the expected ratio of their periods, TC/TS? Assume that D = S, rnS = 0.20kg, and mC = 0.8 kg. 2.58198889747161 1,71124061893542 2.977681801611224 2.21151204168320 Question 9 1 pts Consider a ray incident on the end of a fiber-optic cable as illustrated in the figure below. In the nts experiment, you will ex-plore the behavior of the fiber as a function of the angle of incidence a. When a ray strikes the end of the fiber it is bent toward the normal. By Snell's law, the angle inside the core is sincore = (no1) sin a. Once inside the core, the ray travels until it strikes the cladding of the fiber. The angle of incidence at the cladding i is the complementary angle of Ocore. If i is a small angle, the ray will propagate into the cladding and be lost from the fiber. If i is large, however, the ray will be internally reflected and bounce down the fiber. By Snell's law, the critical angle for the ray to be internally reflected is sin icrit = n21. In the experiment, you cannot directly measure angles inside the fiber but you can measure a. Using the facts that, (i) for complementary angles, sine core = cos i, (ii) the trigonometric identity cos i = v 1 - sini, and (iii) the index of refraction of air is no = 1, it can be shown that sin Ocrit = , 2-n,2 . This quantity is known as the numerical aperture (N.A.) of the fiber. For a cable with a core that has an index of refraction of 1.5 and a cladding with an index of refraction of 1.38, what do you expect the critical angle acrit to be (in degrees)? Cladding - Core refracted ecore reflected hive 36.0065360918641 17.0050589025239 14.6497270972391 O 77.6048882466208D Question 13 0.5 pts If the diagram has no aw, determine in which medium the waves travel more quickly. Can not tell Bottom medium Top medium This diagram has a aw. D Question 14 0.5 pts This ray diagram has a flaw.(True/False) False TrueD Question 15 0.5 pts If the diagram has no aw, determine in which medium the waves travel more quickly. Bottom medium Top medium Can not tell This diagram has a aw D Question 16 0.5 pts This ray diagram has a flaw.(True/False) True O FalseQuestion 17 0.5 pts If the diagram has no aw, determine in which medium the waves travel more quickly. " This diagram has a aw. Top medium Bottom medium Can not tell