1. Draw a best linear fit line on each graph
A best fit is a line that best represents the data points. The best fit does not have to touch every data point and does not have to go through the first and last points. Often the beginning and end parts of the data/graph may exhibit some nonlinearity would be excluded from a linear fit.
2. Determine the slope of each graph
A slope calculation can be done right on the graph. Slope is calculated using widely spaced locations on the drawn line (not from the data points plotted). Use the point format of slope
slope = ------
with two points from your line (avoiding your data points). Units form part of the slope value. Always calculate slope to a decimal value (do not present slope as a fractional value).
3. Determine the spring constant k for each graph
State the value of k on the graph. Spring constant has units.
4. Summarize in your notebook
Clearly note the slopes and spring constants determined for the spring and elastic used. Write a concluding statement.
- In plotting position with force along the x-axis, the theory of Hooke's law in relating to the graph becomes;
||F = -kx = k(P-P0) = kP - kP0
||P = F/k +P0
|Y = mx + b
|| slope = 1/k