Lab 9: Centripetal Force with a Motor

Centripetal Force with a Motor

Isaiah Hernandez and Tony Wu

Purpose: Develop a relationship between Ꝋ and ω.

Theory/intro: F=ma

Using the free body-diagram for the mass being swung, an equation for the net force on the system can be derived and set equal to the mass of the object times its acceleration (in this case is centripetal acceleration. Omega can be solved arithmetically in terms of :

theta(angle made with the vertical), R(distance from the center of rotation to the start of the string), and L( the length of the string). 

A summary of apparatus/experimental procedure: 

The motor spins the at a higher angular speed which is cause for an increase in total radius and angle theta. Record the time it takes for the apparatus to complete 10 rotations and the height above the ground for the hanging mass during several trials. 

A list/table of your measured data:

 

A list/table of your calculated result(s)/Graphs of your data:

Correlation of Theoretical v. Experimental Values of Omega for each case 

Explanation of your graph/analysis:

Data Tables: 
Once obtaining the time it took for one revolution, we were able to get the amount of rotations per second. Flip that number and get the period (seconds per a single rotation). We then multiplied the period for each case by 2Π which would give the angular velocity. 

Graph: 
The graph above shows how close our value was to the expected value. It is expected to have a correlation of about 1 but we were off by a bit in our experimental values. 

Conclusions:

As we increased the omega of the system, the radius (from the center of rotation to the mass on the x-axis), the angle from the vertical, and the height of the swinging object all increase proportionally.