A 142 cm tall person stands
250 cm from a camera, which has
a 15.0 cm focal length lens. How
big is the image of the person on
the film?
(Mind your minus signs.)
(Unit = cm)

Height of the image is 9.06 cm

Explanation:

As we know that the person is standing 250 cm from the lens

Now we know that the focal length of the lens is

f = 15 cm

now by lens formula we have

now we know by the formula of magnification

now we have

need to see circuit to get time constant