A cell phone of length 10.0cm sits 50.0cm in front of a lens of focal length 30.0cm.
a. Without equations, use a diagram to determine whether the image of the cell phone is real or virtual, upright or inverted, and magnified or reduced. Estimate the magnification from your diagram.
b. Now calculate the magnification and check it against your part (a) answer.
c. A student holds his eye close to the lens and looks through it at the cell phone. Instead of a sharp image, he sees a blur. Why?
d. Now the student backs up until his eye is 80cm from the lens. He sees a clear image, but it looks much bigger than he expected, give the answer to part (b). Why?