a ruler a balance a compass a protractor
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student plans to measure the thermal expansion of a strip of metal as it is heated from 0ºC to 50ºC. Which piece of equipment should he use to measure the expansion?
Possibilities:
- a ruler
- a balance
- a compass
- a protractor

a ruler