23-Feb-2015 Lab #1: Mass on an Inertial Balance

The purpose of this experiment is to determine the mass of the tray in order to find the period of the balance itself.

We used a stand and a c-clamps to attach the photogate at the same level as the balance. The balance is attached to a table using a clamp as well. There is also a piece of tape attached to the balance that is meant to sway between the photogate. The photogate is meant to record the period of the passing of the tape.

With this setup we had to add 100 grams to the balance and record the period.We continued all the way until we reached 800 grams. We also measured the periods of two unknown objects.
Unknown #1: phone
actual mass: 143g
0.370 sec
Unknown #2: motion sensor
actual mass: 191g
0.398 sec



 The graph below shows the increase in the period as more weight was added to the balance.

The formula we used to determine the mass of the tray was T=A(m+Mtray)^n. However, before we can actually use it we make the formula look like the linear equation by natural logging both sides.
By doing that our formula transformed into ln T = n * ln (m + M_tray) + ln A.

 Before we can make the line graph we have to create separate columns with the ln(period) and ln(m+Mtray).

So once the columns were developed we are able to create the best fit line. However, since we do not know the actual mass we have to guess until the correlation is 0.9999. We must find the highest the mass can be and the lowest the mass can be. We came up with a range of 311g to 282g. With the masses we came up with we plugged the values found into T=A(m+Mtray)^n and solved for m (which represents the unknown objects).

 The actual masses of the unknown objects are suppose to be at least within the values that are calculated.

Unknown #1: phone
actual-143g
lowest-145.3g
highest-146.8g

Unknown #2: motion sensor
actual-191g
lowest-195.6g
highest-197.9g

Since the values calculated are off by 2 or 3 grams for both objects there must have been some problems that may have accord during the actual lab.