Question

WILL REWARD 20 more pts once solved

4) If you have a diverging lens with a focal length of -15 cm and it produces an image that is 9
cm from the lens, what is the height of the image if the object was 4,5 cm tall?
b) Draw a ray tracing diagram of the situation below (label all points in cm) :

Answer 1

Step-by-step explanation:

step 1. a diverging lens is "concave" on both side and always has a negative focal length

step 2. so 1/f = 1/s + 1/s' where f is the focal length, s is the object location, and s' is the image location (f, s, s' are all on the left side of the lens)

step 3. 1/-15 = 1/s + 1/-9 (image is virtual (negative))

step 4. 3/-45 = 1/s + 5/-45

step 5. s = 22.5cm (object is 22.5cm from lens)

step 6. s'/s = 9/22.5 ÷ 0.4 (magnification)

step 7. if the object is 4.5cm then the image is 4.5(0.4) = 1.8cm tall.