Pasco Scientific ME-9447, Instruction Manual And Experiment Manual

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5
012-04715B
Force Table
®
EQUIPMENT NEEDED:
ME-9447 Force Table, –3 pulleys and pulley clamps, –3 mass hangers, –mass set, –string, –
metric ruler, –protractor, –2 sheets of paper
Purpose
The purpose of this experiment is to use the force table to experimentally determine the force
which balances two other forces. This result is checked by adding the two forces by using their
components and by graphically adding the forces.
Theory
This experiment finds the resultant of adding two vectors by three methods: experimentally, by
components, and graphically.
Experiment 1: Vector Addition
➤
NOTE: In all cases, the force caused by the mass hanging over the pulley is found by
multiplying the mass by the acceleration due to gravity.
Experimental Method
Two forces are applied on the force table by hanging masses over pulleys positioned at certain
angles. Then the angle and mass hung over a third pulley are adjusted until it balances the
other two forces. This third force is called the equilibrant ( F
E
) since it is the force which
establishes equilibrium. The equilibrant is not the same as the resultant (
F
R
). The resultant is
the addition of the two forces. While the equilibrant is equal in magnitude to the resultant, it is
in the opposite direction because it balances the resultant (see Figure 4). So the equilibrant is
the negative of the resultant:
– F
E
= F
R
= F
A
+ F
B
Figure 4 The Equilibrant Balances the Resultant
F
E
F
R
F
B
F
A