Thursday, January 29, 2015

As discussed in my previous blog, Torque= Force x Lever Arm. Torque is what causes something to rotate and fall down. That means that in order to balance an object it must have equal torques. One must also locate the center of gravity, if it is with in the base of support, the object will be able to balance. For example, in class we tested the rules of balancing by balancing a meter stick. We were asked to record the measurements we took and the various procedures we tried Furthermore, we taped a 100g weight to one end and rested the other on the table.




We know now that we would need the following equations.
Torque= F x Lever arm

w=mg (Weight= mass x gravity)

In the picture above, the two downward arrows represent the Fweight. The triangle represents the center of gravity. Lastly, the lines across the top represent the lever arm. Go ahead and pretend this ruler is actually a meter stick.

Layton and I were able to locate the center of gravity by finding a place of balance after a few wobbly tries. The center of gravity was located at the edge of the table.  We found this location to be at the 30.8 cm mark. From here we could easily find the lever arms. The half not in contact with the table had a lever arm d 30.8cm and the other half had a lever arm of 19.2cm.

Because we know that the force is 9.8 the rest of the torque equation was easy.
Torque= (9.8) x (30.8)
Torque=30.18
Because we know the torque is equal, we know that both sides have a torque of 30.18.
Now we just need to find the force of the half without the weight.
Torque= (F) (Lever arm)
30.18=(F) (19.2)
30.18/19.2=1.57
F=1.57

Now we use the other equation w=mg.  This will convert the force to mass.
1.57= m x 9.8
1.57/ 9.8 =m
0.160kg = mass
In order to convert 0.160kg into grams, we just move the decimal. Furthermore, we found the mass to be 160 grams. This was only 13 grams off from our actual weight, which turned out to be 147.6g
Below is a picture! We were close!


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