Principle Of A Meter Stick

1296 Words 6 Pages
Suhani Shah & Emma Bekhet

Purpose: To develop an efficient and accurate method of using torque to mass a meter stick – without using a triple beam balance or spring scale / force meter. Materials:
One meter stick
One fulcrum
Three sliding Clips
One 50 gram hanging mass

Setup fulcrum
Attach a sliding clip at the 50 cm mark of the meter stick and place meter stick on a fulcrum.
From that point, move the sliding clip left and right (based on which side of the meter stick is going down/up) until you are able to identify a precise value for the center of mass. If the right side of the meter stick is going down than the clip should be moved towards the right side. Vice versa for the left side. Once the meter stick stops moving,
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This will not be found at the center of mass because one of the clips is considerably heavier than the other (because it has a hanging mass). All three clips and the fulcrum should be moved. It helps to see which side of the meter has the mass. The mass and distance of one side are indirectly proportional, meaning as one value gets bigger, the other value gets smaller. As indicated in the picture above, the side that has the bigger mass has a smaller distance from the fulcrum while the side with the smaller mass has a larger distance from the …show more content…
More traditional tools for measuring mass are spring scales and triple beam balances. Discuss in terms of forces and torques how each of these tools can be used to determine the unknown mass of an object. Include in your discussion an explanation as to why mass measurements taken by a spring scale are affected by local variations in gravitational field strength, while those taken by a balance are not.
The way a triple beam balance works has to do with the idea that equal masses on each side are being pulled downwards by gravity with equivalent forces. As mentioned before, torque can be obtained by multiplying the mass of the weight, times the force of gravity, times the distance from its pivot point or the fulcrum (T=m*g*l). When the balance reaches equilibrium, the torque that is created by the measured object must equal the torque applied to the other side of the balance. In order to make both torques equal, the masses along the beam of the balance must be moved away from the pivot point, or the fulcrum. By moving these masses, the torque is changing since the length of the lever arm is also changing. Rotational equilibrium is reached when the torque acting on each side of the pivot point are

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