What is the position, and the size, of the image of a 7.6 cm high leaf placed 1.00 m from a 50 mm focal length camera lens?

Use the lens formula: 1/v = 1/f − 1/u. Here f = 5 cm and u = 100 cm, so 1/v = 1/5 − 1/100 = 19/100. This gives v = 5.26 cm.

Magnification = v/u = 5.26/100 = 0.0526. Image size = 0.0526 × 7.6 cm = 0.40 cm. The image is small because the leaf is far away compared with the focal length.