Calculate the circumference (including uncertainty) of a circle whose measured radius is r=7.3 ± 0.2cm.
2.Relevant equations & 3.The attempt at a solution
- Circumference of circle --> C = 2πr = 2π7.3 = 45.87 cm
- Exact constant error propagation --> z = kx
- Limit Error --> δz = kδx
- Therefore, δC = 2π(0.2 cm) = 1.257 cm
Final Answer = 46 ± 1 cm
OR Should I be going about it like this:
- Circumference of circle --> C = 2πr = 2π7.5 = 47.124 cm = 47 cm
- Circumference of a circle --> C = 2πr = 2π7.1 = 44.611 cm = 45 cm
- Final Answer 46 ± 1 cm
I was discussing this with someone else. I did it the first way and they did it the second way.
Also, my final answer has the correct significant figures right?