PASCO ME-6844 Parallel Spring Bracket - Manual (Page 4)

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P a r a l l e l S p r i n g B r a c k e t M E - 6 8 4 4
4
(eq. 4)
The axis about which the torques are measured is chosen to be at
the “0 cm” mark. Spring #1 is attached at the axis, therefore its
torque is zero. The net torque is
(eq. 5)
Solving for F
s2
yields:
(eq. 6)
Combining equations 4 and 6 gives us:
(eq. 7)
Period of Oscillation
The period of oscillation of a mass on a spring (or combination of
springs) is
The mass, m, should include the hanging mass, the mass of the
hook bar, and 1/3 of the mass of the springs.
To demonstrate this relationship for any combination of springs,
use a stop watch to measure the period of oscillation. Increase the
hanging mass in steps. Make a graph of T
2
versus ∆m. The slope
of the best-fit line is 4
π 2
/k.
Sensor-based Measurement
To measure the spring
constant using a rotary
motion sensor (RMS)
and a force sensor, set
up the equipment as
illustrated. Pull the
force sensor to stretch
the spring combination.
Make a graph of force
(measured by the force
sensor) versus linear
position (measured by
the RMS). The slope of
the best-fit line is the
spring constant.
Storage
To keep the bracket and hook bar together when not in use, clamp
the hook bar under the thumbscrews as illustrated.
Technical Support
For assistance with any PASCO product, contact PASCO at:
Limited Warranty For a description of the product warranty, see the
PASCO catalog.
Copyright
The PASCO scientific 012-09843A Parallel Spring Bracket
Instruction Sheet is copyrighted with all rights reserved. Permission is
granted to non-profit educational institutions for reproduction of any part of
this manual, providing the reproductions are used only in their laboratories
and classrooms, and are not sold for profit. Reproduction under any other
circumstances, without the written consent of PASCO scientific, is prohib-
ited.
Trademarks
PASCO, PASCO scientific, DataStudio, PASPORT, and
Xplorer GLX are trademarks or registered trademarks of PASCO scientific,
in the United States and/or in other countries. All other brands, products,
or service names are or may be trademarks or service marks of, and are
used to identify, products or services of, their respective owners. For more
information visit www.pasco.com/legal.
F
net
F
s1
F
s2
mg – + 0 = =
τ
net
r
s2
F
s2
r
m
mg – 0 = =
F
s2
r
m
r
s2
------ mg =
F
s1
1
r
m
r
s2
------ –
 
 
 
mg =
T 2
π m
k
---- =
Address: PASCO scientific
10101 Foothills Blvd.
Roseville, CA 95747-7100
Phone: 916-786-3800 (worldwide)
800-772-8700 (U.S.)
Fax: (916) 786-7565
Web: www.pasco.com
Email: [email protected]