24-Aug-2014 Lab #1 Pendulum Timer

This lab was designed for students to find a relationship between mass and period for an inertial balance as stated in our packet. This means that in order to find the mass of an unknown object we must measure the times in which our inertial balance moves back and forth between a photogate which will record and create a formula on Logger Pro using the times gathered at different masses.

This is the basic set up of the beginning of the lab. On the left on the pole is the photogate which timed the periods the tape attached to the inertial balance passes through.

 After every period was recorded we added 100 grams. The one being shown in the picture above is at 600 grams.

The chart above shows the mass that was on the inertial balance and also contains the period in which it took for it to pass through the photogate.

This graph represents the chart previously according to the masses put and the periods recorded with the photogate. There is a linear fit line between the data points to represent the accuracy of the data.

The picture above represents the data we recorded except in natural logarithmic form. We need this data to create a graph.

With this graph we test different masses in order to get the closest possible connection which is 0.9999. The max we got with was .3kg with a min of .24kg. Once this is gathered, we had to figure out our two unknown masses by plugging in the information given in the graph above with the formula T=A(m+Mtray)^n.

However, before we do this we test the unknown objects on the inertial balance and photogate to get there periods.

The first unknown mass object was my galaxy S4 with a period of 0.373386 second.

The second unknown mass object was a half full Arrowhead water bottle at a period of 0.510300second.

With theses periods we were able to complete the formula and solve for max and min masses of the objects.

Phone (unknown 1):

m max-.134kg

m min-.131kg

actual mass-.132kg

Arrowhead Water Bottle (unknown 2):

m max-.394kg

m min-.390kg

actual mass-365kg

The whole lab was based on physical data recorded on a inertial balance and photogate. With that we created a graph on Logger Pro with natural log data calculated. Then we used the x,y, and b on the linear fit line and plugged it into the equation T=A(m+Mtray)^n along with the periods of the unknown objects to solve for the max and min mass of the objects.