Spring Stretch Picture Lesson:
Designed by: Martha DiCredico
Temple University: College of Education
Summary Purpose
of this Inquiry Lesson
• A spring will stretch when mass is suspended
from it. As more mass is added, the spring will
stretch more. Let’s see how stretchy our
springs are!
Materials:
Tape, Paperclip, 3 springs, 6 large washers, ruler
with centimeters
We have taped a spring that is 7.5 centimeters to the edge of a
table. Let’s see what will happen when mass is added.
We can use a large paperclip to attach to the spring to add mass. By adding 1
large washer we made the spring stretch to 7.7 centimeters. We must
subtract the original length of the spring from this number.
7.7 cm – 7.5 cm = 0.2 cm of spring stretch
Now we have added a second washer, and the spring is now 7.8 cm long. We
don’t forget the calculation. 7.8 cm – 7.5 cm = 0.3 cm of spring stretch
After we have added 3 large washers and our spring has stretched to 8.7
centimeters. Our calculation is 8.7 cm – 7.5 cm = 1.2 cm of spring stretch
After adding 4 large washers our spring has stretched to 9.8 centimeters.
We calculate 9.8 cm – 7.5 cm = 2.3 cm of spring stretch
When we add 5 large washers our spring stretched to 11 centimeters.
We can calculate 11 cm. – 7.5 cm. = 3.5 cm. of spring stretch
Finally, we add 6 large washers to make the spring stretch to 12 centimeters.
We can calculate 12. cm – 7.5 cm = 4.5 cm of spring stretch.
Here is the smallest of the three springs measuring at 2 cm. Let us see what
kind of spring stretch this spring has.
When we added 1 heavy washer the spring stretched to 2.3 centimeters.
We calculate 2.3 cm – 2.0 cm = 0.3 cm of spring stretch
When we add another washer the spring stretched to 3.0 centimeters.
We calculate 3.0 cm – 2.0 cm = 1.0 cm of spring stretch
By adding a third washer the spring stretch to 3.3 centimeters.
We calculate 3.3 cm – 2.0 cm = 1.3 cm of spring stretch
Adding 4 heavy washers made the spring stretch to 3.8 centimeters.
We calculate 3.8 cm – 2.0 cm = 1.8 cm of spring stretch
Adding a fifth heavy washer made the spring stretch to 4.0 centimeters.
We calculate 4.0 cm – 2.0 cm = 2.0 cm of spring stretch
By adding 6 heavy washers we were able to make the spring stretch to 4.3
centimeters. We calculate 4.3 cm – 2.0 cm = 2.3 cm of spring stretch
What is going on here?
• When mass is added to the spring the force of
gravity pulls it downward.
• There is force in the spring called restoring
force which is pulling back on the mass. The
force of gravity and the restoring force are
equal in size and opposite in direction
Lets try a spring that is 4.5 centimeters long.
How much spring stretch will we find?
Adding one heavy washer did not stretch this spring.
Adding a second washer made the spring stretch to 4.6 centimeters.
We calculate 4.6 cm – 4.5 cm = 0.1 cm of spring stretch.
Adding a third washer made the spring stretch to 4.7 centimeters.
We calculate 4.7 cm – 4.5 cm = 0.2 cm of spring stretch.
Adding a fourth washer did not make the spring stretch any further than
adding 3 washers.
Adding a fifth washer made the spring stretch to 5.3 centimeters.
We calculate 5.3 cm – 4.5 cm = 0.8 cm of spring stretch
Adding six heavy washers made the spring stretch to 6.0 centimeters.
We calculate 6.0 cm – 4.5 cm = 1.5 cm of spring stretch
The more mass added the more the
spring will stretch.
• A stiffer spring will not stretch as much as a
loose spring. This simple experiment just
determined the “Spring Constant” of a spring
which tells us how “stretchy” a spring is.
Student Sample: Data Table
Amount of Spring Stretch
Number of Washers
Spring #1
2 cm long
Spring #2
4.5 cm long
Spring #3
7.5 cm long
1
0.3 cm
0.0 cm
0.2cm
2
1.0 cm
0.1 cm
0.3 cm
3
1.3 cm
0.2 cm
1.2 cm
4
1.8 cm
0.2 cm
2.3 cm
5
2.0 cm
0.8 cm
3.5 cm
6
2.3 cm
1.5 cm
4.5 cm
Average Spring
Stretch
1.45 cm
of spring stretch
0.46 cm
of spring stretch
2.00 cm
of spring stretch
Student Sample: Chart of the Data
Links to Internet Resources for this
Inquiry Picture Lesson:
• Create a Graph:
http://nces.ed.gov/nceskids/createagraph/def
ault.aspx
To see other picture lessons go to…
http://science-inquiry.wikispaces.com