Question

Shawn wanted to find out which of the four materials A, B, C and D allows the most light to pass through. He was given the following items:
- A torch
- A ruler
- A light sensor connected to a datalogger
- Four different materials A, B, C and D
Shawn carried out his experiment in a dark room

Why must Shawn conduct his experiment in a dark room?

Answer 1

If the arrangement is correct you really don't need a dark room; however, I assume the arrangement was not right. In this case, the light from the room would be measured and that isn't what you want.