A person on a safari wants to take a photograph of a hippopotamus from a distance of 78.8 m. The animal is 4.90 m long and its image is to be 1.24 cm long on the film.
(a) What focal length lens should be used?
___mm
(b) What would be the size of the image if a lens of 50.0-mm focal length were used?
___ mm
(c) How close to the hippo would the person have to be to capture a 1.24-cm-long image using a 50.0-mm lens?
___ m