Name __________________________________________ Per ______ Date ________________
GRAPHING EXPERIMENTAL DATA 1
When a force is applied to an object, the object may be stretched, Equipment
compressed, bent, or twisted. These deformations occur while the force Hooke’s Law apparatus
acts on the object. Within limits, when the force no longer acts on the coil spring
object, that object returns to its original shape. You must take care not to ring stand
hang too heavy a weight on your spring or steel strip. Too much weight clamp
may cause either one to be deformed permanently. metric ruler
masking tape
large paper clip
Objectives steel strip
During this investigation you will masses
graph experimental data. 1 – 500g (ruler support)
interpret the graph to develop relationships between variables. 1 – 50g
2 – 20g
Procedure 1 – 10g
A. Using a Spring
1. Inspect your apparatus. You will use this apparatus to measure the
stretch of the spring as various forces are applied to it. Hang the
spring from a firm support. Devise some sort of pointer that can be
attached to the spring to measure how much each mass stretches
the spring. The stretch of the spring is the difference between the
position of the pointer when no load is on the spring and its
position when a load is on the spring.
Figure 1-1. Read the elongation with the pointer at eye level and from directly in front.
2. Read and record in Table 1-1 the position of the pointer with no
load on the spring.
3. Attach more and more mass and observe each corresponding
extension of the spring. Record your observations in Table 1-1.
Take all readings by looking straight on at the pointer not by
looking from above or below.
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B. Using a Steel Strip
1. Set up the apparatus as shown in Figure 1-2. Clamp one end of the
steel strip securely. Hook a bent paper clip over the other end and
place a piece of tape at the end of the strip to prevent the clip from
falling off. Measure the amount of bending as more and more
masses are hung from the clip. Record your measurements in Table
1-2.
Figure 1-2. Record the vertical displacement of the steel strip as amount of bending.
Data and Calculations
Table 1-1 Data Calculations
Reading with Reading with Elongation of
Mass (g)
no load (cm) load ( cm) spring (cm)
10.0
20.0
40.0
60.0
80.0
100.0
Uncertainty = ± ________ cm Unc. = ± _________ cm
Table 1-2 Data Calculations
Reading with Reading with Bending of
Mass (g)
no load (cm) load ( cm) steel strip (cm)
10.0
20.0
40.0
60.0
80.0
100.0
Uncertainty = ± ________ cm Unc. = ± _________ cm
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Interpretation
Be sure each graph has a title, and all axes are labeled properly. Show error bars for the uncertainty in
elongation or bending, and draw a BEST FIT line on each graph.
1. a. Graph the data in Table 1-1. Be careful to plot the dependent and independent variables on the
correct axes.
b. Graph the data in Table 1-2 in the same way you did for Step 1(a).
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Name __________________________________________ Per ______ Date ________________
Interpretation
2. What is the NAME of the mathematical relationship between the stretch of the spring and the amount
of suspended mass shown by graph 1.a.? What about the GRAPH'S SHAPE shows that this is the
relationship named?
_____________________________________________________________________________________
_____________________________________________________________________________________
3. Show your work next to graph 1 a. to FIND THE SLOPE of the line then WRITE THE
EQUATION of the line of this graph in the space below.
4. Use your equation from question 3 to PREDICT THE ELONGATION of the spring due to a 500.0
gram mass. Show your work and box in your answer.
5. What is the NAME of the mathematical relationship between the bending of the steel strip and the
amount of hanging mass shown by graph 1.b.? What about the GRAPH'S SHAPE shows that this is
the relationship named?
_____________________________________________________________________________________
_____________________________________________________________________________________
6. Show your work next to graph 1.b. to FIND THE SLOPE of the line then WRITE THE
EQUATION of the line of this graph in the space below.
7. Use your equation from question 6 to PREDICT THE BENDING of the steel strip due to a 50.0
gram mass. Show your work and box in your answer.
8. Question 4 above is an example of EXTRAPOLATION which is using the equation of the line to
predict a value BEYOND the range of the gathered data. Question 7 above is an example of
INTERPOLATION which is using the equation of the line to predict a value WITHIN the range of
the gathered data. Which is MOST LIKELY to result in an wrong predicted value? Why?
_____________________________________________________________________________________
_____________________________________________________________________________________
9. The pointer of a spring scale moves 2.0 cm when a force of 9.8 N is added to it. HOW MANY cm
will a 45 N force cause the pointer to move? Show your work and box in your answer.
10. A force of 50.0 N causes a steel rod to twist through 2.0 degrees of arc. Through HOW MANY
DEGREES OF ARC will a force of 125 N cause the same rod to twist? Show your work and box in
your answer.
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