An engineer wishes to determine the spring constant of a helical spring. She first puts enough weights on the spring to pull the coils apart. Using a simple wooden meter stick with millimeter marks, she finds that the elevation of the end of the spring changes from 63.5 cm to 52.6 cm when she adds a lab weight whose stamped value is 400 grams. The uncertainty of the stamped weight is 2%. Take g = 9.81 m/s2 with negligible uncertainty.
a. What is the best estimate of the spring constant? (in N/cm)?
b. What is the uncertainty in the value of the spring constant? (in N/cm)