PASCO ME-6992B Advanced Structures Set - Manual (Page 22)

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A d v a n c e d S t r u c t u r e s S e t H u m a n B a c k M o d e l
18 012-12719B
Human Back Model: Details
Force Vector Diagram
The following diagram shows the force vectors acting on the human back model.
Load Cells
The Load Cells directly measure the forces exerted on the back model. The structure is shown with four Load
Cells measuring the horizontal and vertical forces of the axle at the base of the ‘spine’. The experiment can be
performed using only two Load Cell (both on one side) but care must be taken to ensure that the ‘spine’ is cen-
tered and balanced side-to-side. The actual force is thus twice the measured value.
Suggestions
Experiment with the ‘back’ at different angles and use the Load Cell to measure the tension in the cord.
What is the affect of increasing or decreasing the angle of the ‘back’?
Experiment with the amount of weight attached to the end of the ‘arm’.
Does doubling the weight also double the tension in the cord attached to the Load Cell?
What happens to the horizontal and vertical forces at the base of the ‘spine’?
W
W
b
T
F
y
F
x
Cord
Weight
Load Cell
Amplifier
Slotted
Masses