Hooke’s Law Lab
Name:__________________________________________________
Date:________________
Mod:________________
Pre-Lab Questions:
1. Define Hooke’s Law.
2. Describe the elastic limit and how it affects Hooke’s Law.
3. In the Lab, what is the maximum amount of metal washers to be placed on the springs?
4. In the Lab, what is the dependent and independent variables for the graph?
Purpose: To determine the relationship between the forces applied to a spring and the amount the
spring stretches. The use of Hooke’s Law will be used to calculate the spring constant of
different springs.
Materials:
-
Hooke’s Law Apparatus
Stiff Spring
Loose Spring
Metal washers (8)
Balance
Procedure:
1. Place the Hooke’s Law apparatus on a flat level surface.
2. Attach one of the unknown springs that have a black line down
the side of it to the stretch indicator (Neon orange disk) and hang
it from the notch on the support arm of the apparatus.
3. Connect the blue mass hanger to the bottom of the stretch
indicator. To connect the mass hanger, unclip the bottom wire
clamp and slide the clamp through the slit on the hanger.
4. Align zero on the sliding transparent scale with the stretch
indicator attached to the pole of the stand. The final setup should
look like the apparatus shown to the right.
5. Once everything is set up, it’s time to start recording data. Take
two washers and find their mass using the balance. Enter their
mass in grams in the table below.
6. Place the two washers on the mass hanger and record how far the stretch indicator dropped in
centimeters.
7. Take the two washers off the mass hanger. Now take 4 washers and find the mass of those
using the balance and record. Then place the 4 washers on the mass hanger and record how far
the stretch indicator dropped.
8. Repeat the same step as #7 for the 6 washers and 8 washers. Record your data.
9. Once finish collecting data for spring #1 (Black Line), remove the spring and replace it with the
spring that doesn’t have a line on it. Reset the stretch indicator to zero on the transparent
scale.
10. Repeat steps #5 through #8 for spring 2 and record your data in the table below.
Hooke’s Law Lab
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11. Once all the data is collected, convert grams to kilograms and then to Newton’s. Also convert
centimeters to meters in the data table.
12. Make a graph of Force vs. Displacement using Microsoft Excel or on graph paper. Record the
data for spring #1 and spring #2 on the graph where force (N) is the dependent variable and
displacement (m) is the independent variable.
13. Provide a key on the graph to distinguish between the two different springs.
14. Make a line of best fit for both springs. Using the slope intercept form for a linear equation,
write an equation for each of the springs. Make sure to include appropriate variables, numbers,
and units in the equation. All work for and equations can be placed on the graph.
Data Table:
Spring
#1
(Black
line)
2
washers
4
washers
6
washers
8
washers
Mass of Mass of
washers washers
(g)
(kg)
Weight
Force
(N)
Displacement Displacement
(cm)
(m)
Spring
Mass of Mass of
#2
washers washers
(No line)
(g)
(kg)
2
washers
4
washers
6
washers
8
washers
Weight
Force
(N)
Displacement Displacement
(cm)
(m)
Post-Lab Questions:
1. What does the slope of the Force vs. Displacement graph show? What does the vertical
intercept represent on the graph?
2. Calculate the percent error of the spring constant for each spring. The actual spring constant of
spring #1 is 8 N/m and spring #2 is 5 N/m.
3. What factors do you think may have caused there to be a difference between the actual spring
constant and the measured spring constant? Give at least 3 errors and explain why they cause
errors to the data.
Hooke’s Law Lab
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