PASCO ME-6855 Tension Protractor - Manual (Page 11)

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T e n s i o n P r o t r a c t o r E x p e r i m e n t 2 : B o o m i n S t a t i c E q u i l i b r i u m
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6. Clamp the Tension Protractor near the top of the vertical rod.
7. Zero the force scale of the Tension Protractor: Without anything attached to the Ten-
sion Protractor string, adjust the thumb screw in the back until the force scale reads
zero.
8. Zero the angle scale of the Tension Protractor: Hang a small mass (10 g) from the
hook. Rotate the outer ring to align the 90° mark with the string (Figure 2.2).
9. Tie a string to the hook of the Tension Protractor. Use a piece of string that is long
enough to reach the free end of the meter stick with the stick being approximately
horizontal. Tie the other end of the string to the end of the meter stick, keeping the
meter stick approximately horizontal. Keep the meter stick and the face of the Tension
Protractor in the same plane, and keep the pivot rod perpendicular to that plane.
10. Hang the 500 g mass from the loop of string around the meter stick at about the 60 cm
mark.
11. Use the level to determine if the meter stick is horizontal. Make the stick level (hori-
zontal) by changing the height of the pivot clamp or the height of the Tension Protrac-
tor. Or, for small adjustments, move the hanging mass, but keep it between the 55 cm
and 65 cm marks.
12. Record the angle of the string in Table 2.1.
13. Record the tension in the string in Table 2.1.
14. Record the distance from the pivot to the point where the string is attached to the
meter stick in Table 2.1.
15. Record the distance from the pivot to the hanging mass in Table 2.1.
16. Record the distance from the pivot to the center of mass of the meter stick in
Table 2.1.
Analysis
1. Calculate the clockwise torques about the pivot caused by the hanging mass and the
stick and record them in Table 2.2. Calculate the total clockwise torque and record it
in Table 2.2.
2. Calculate the counterclockwise torque about the pivot caused by the tension in the
string and record it in Table 2.2. (Don’t forget to account for the angle!) Calculate the
total counterclockwise torque and record it in Table 2.2.
Figure 2.2: Zero the
angle scale
Table 2.1: Data
Mass of meter stick
Mass of hooked mass
Center of mass of meter stick
Angle of string
Tension
Distance from pivot to string
Distance from pivot to hanging mass
Distance from pivot to center of mass of meter stick