please help me with optics and wave interactions!! 1). A 12 cm tall object is placed 16 cm to the left of a convex lens which has a focal length of 9 cm. a). Where will the image form? (image distance) b). What kind of image is formed? 2). A 15 cm tall object is placed 30 cm to the left of a concave lens. An image forms 9 cm to the left of the lens. a). What is the magnification of the image? b). How tall will the image be? 3). Suppose the index of refraction for a substance is 2.0. How fast will light travel through this substance? 4). A material has an index of refraction of 1.75. What is the critical angle for this material? 5). The critical angle for cubic zirconium is 29.2 degrees. What is the index of refraction? 6). A piano tuner wants to tune a particular string to vibrate at 330 Hz. Suppose when he strikes the string with a 330 Hz tuning fork, he hears 180 beats in one minute. Which of the following is a possible frequency for the string?