Question

A man 2m tall stands 3m from a pinhole camera. How is the image in the camera affected when the man moves 1m close to the camera?

Answer 1

The image will increase in size according to the following equation for image height:

$$\frac{h_o}{d_o}=\frac{h_i}{d_i},\\\space\\ h_i=h_o\frac{d_i}{d_o} .$$

Object distance decreases - image size increases.