Two plane mirrors are facing each other, placed on opposite walls of a room. The mirrors are separated by a distance D. A vase is placed at the midpoint between the mirrors. An infinite number of images of the vase are created in each mirror. (Try this at homet) The first image created in each mirror is of the vase itself, and those images are separated by a total distance 20. For the above scenario, derive an expression in terms of D for the distance between any corresponding pair of images in both mirrors. You should use a variable like n to indicate the pair of coresponding images to which you are referring. For example, the first set described here would be n- 1. The second set (n - 2) would be the images of the first set (n- 1) created in each opposite mirror, and so on. (Use the following as necessary: D and n.) Need Help? Read

r AB= ? in (I+j+k)

A homogeneous pulley with two grooves consists of two wheels which turn together as one around the same axis. The moment of inertia of the two wheels together is ICM = 40 kg m2. The radii are: R1 = 1.2 m and R2 = 0.4 m. The masses that hang on both sides of the pulley are m1 = 36 kg and m2 = 12 kg. We will assume that the masses of the ropes are negligible. Determine the angular acceleration of the pulley, acceleration of the masses, and the tensions of the ropes.

C is incorrect and D was not answered. I'm struggling with how to get the correct answer for C