a camera phone called the Iphone X has an image sensor size of 8.

a camera phone called the Iphone X has an image sensor size of 8.5mm.

a) what focal length must the lens have in order to get the same angle of view as a 50 mm lens on 35 mm film

b) if the size if a pixle occupies 1um^2 how many pixels does a picture taken with the 8.5mm x 8.5mm sensor have