Plotting graph and data analysis: Plot T2 vs. hanging mass. T2 should be in seconds (y-axis) and hanging mass should be in kg (x-axis). Use Excel to find the best fit line. The slope of the best fit line will allow you to m determine the spring constant, k. Remember that T =2x k If we square both sides of this equation we get: 12 = 1m Since we have plotted T2 vs. m, then the slope of the best fit line is related to the spring constant. The spring constant k = (4x2 /slope). From your best fit line, determine the slope and the spring constant. Slope:. m/N k = (4x2 /slope) = N/m Calculation: (show your calculation) Calculate the percent difference between spring constants found in parts I and II. Do this by taking the absolute value of the difference of the two spring constants and dividing by the average of the two spring constants. % Difference = K - K2 X100% : k, + kzy