1. Starter What is the spring constant for this spring?
What is the meaning of the y-intercept?

2. Starter Hooke’s Law
If a 1kg mass stretches a spring 2.5cm, what mass would stretch it 10cm?

3. Hooke’s Law for Springs
The force required to stretch a spring is directly
proportional to how much it is stretched, or :
F = kx
F = stretching force in Newtons
x= stretch in meters
k = the spring constant in N/m

4. Example When a .5kg mass is hung on a spring, it stretches .25m.
1. What is the spring constant?
k = F/x = mg/x = .5(9.8)/.25 = 19.6 N/m
2. How much would a 2kg mass stretch the spring?
x = F/k = 2(9.8)/19.6 = 1.00m

5. Hooke’s Law F =kx If you plot the stretching force on the y axis,
and the amount of stretch on the x axis, what
will the plot look like?
What does the slope
represent?
Slope = k

6. Practice - Hooke’s Law P m (kg) x(m) F (N) 0.00 0.00 .050 .045 .441
0.00 
.050
.045
.441
0.100
0.090
.980 P

7. Elastic Forces - Hooke’s Law
F = kx
k = 10.9 N/m

8. Application - Springs A
Design an experiment to determine the spring constant for:
2 of the color coded springs
1 of the silver springs.
A rubber band
Make a F vs. x graph for each with 5 data points.
Show a best fit line and determine the equation and k. A

9. Sample Data table Spring Color ______________ Trial m (kg) x(m) F (N)
Plot on x-axis
Plot on y-axis
Trial
m (kg)
x(m)
F (N) 1 2 3 4 5

10. Question
Did the rubber band obey Hooke’s Law? Explain.

11. Lab Report Checklist Starter Data Tables (4)
F vs. x Graphs (4) with slopes
Experimental k values (4)
Question
Connection
Summary

12. Connection C What real life applications of Hooke’s Law
have you observed? C

13. EXIT E Summarize your experiment including the objective,
the procedure, the results, and reasons for error. E