Theory, Procedure – PASCO ME-8092 Force Distribution Apparatus User Manual
Page 3
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M o d e l N o . M E- 8 0 9 2
T h e o r y
3
4.
Repeat the process to attach a second force sensor.
5.
Mount the apparatus on a horizontal rod as shown below. (Note that both force
sensors face the same way.)
6.
Position the motion sensor at the height of the ball and 15 to 20 cm from the end
of the beam.
7.
Incline beam slightly so the ball rolls slowly away from motion sensor.
8.
Open the DataStudio file Force Distribution.ds from the included CD-ROM.
Connect the force and motion sensors to a PASPORT interface (or interfaces).
Connect the left force sensor first followed by the right force sensor.
Theory
As the ball rolls along the beam, the beam remains in static equilibrium. The criteria
for static equilibrium of an extended body are
•
the sum of all the external forces is zero:
•
and the sum of all the external torques is zero:
As the ball changes position, the force exerted by each force sensor changes, but the
net force exerted by the ball and both force sensors remains constant at zero. Also, the
torque exerted by the ball changes (because the ball’s lever arm changes), but the net
torque exerted by the ball and both force sensors remains constant at zero.
Procedure
1.
Set up the apparatus with two force sensors at the inner attachment points.
2.
Measure the mass of the ball.
3.
With the ball removed from the beam, press the zero buttons (or tare buttons) on
both force sensors.
4.
In DataStudio, view the graph of position versus time
1
If you are using three
PASPORT force sen-
sors, open the file
Force
Distribution (3 force).ds.
Connect the left, right,
and center force sensors
in that order.
2
If you are using
ScienceWorkshop sen-
sors, see page 5 for
instructions.
F
net
Σ
F
0
=
=
τ
net
Στ
0
=
=