A 1.5 m tall person is standing at a distance of 3 m from a lamp post. The light from the lamp at the top of the post ca...

Question

A 1.5 m tall person is standing at a distance of 3 m from a lamp post. The light from the lamp at the top of the post casts her shadow. The length of the shadow is twice her height. What is the height of the lamp post in meters?

A. 1.5
B. 3
C. 4.5
D. 6

Accepted Answer

Height of lamp post = 3 m — Option B The lamp at the top of the post shines on a person standing 3 m away. The shadow length equals twice the person's height, that is 3 m, so the shadow tip is 3 m beyond the person. Using similar triangles formed by the lamp, the person, and the shadow tip, we find the lamp height.

A 1.5 m tall person is standing at a distance of 3 m from a lamp post. The light from the lamp at the top of the post casts her shadow. The length of the shadow is twice her height. What is the height of the lamp post in meters? A. 1.5 B. 3 C. 4.5 D. 6