Topics: Force, Kinematics, Mass Pages: 4 (1003 words) Published: December 11, 2012
Centripetal Force: The center-seeking force
Group Members:
Joshua Velez, Patrick Hannigan-Devine, and Eric Guidarelli
PURPOSE:
To move in a circle F=ma is required, where acceleration being the rate of change of velocity with velocity being both magnitude and direction. Magnitude of acceleration can be found by a=v2R. The relation of these two is found in centripetal force F=mv2R. This lab will prove the relation of the first two equations. EQUIPMENT:

* Centripetal Force Apparatus
* Mass Balance
* Mass Set
* Eye Protection
* Mass Hanger
* Level
* Stopwatch
* Ruler

Draw two Force Diagrams: Draw separate diagrams for the bob and for the hanging mass

Fg
Fg
FT
FT
Fg
Fg
FSpring
FSpring
FT
FT
FT
FT

QUESTIONS WITHIN PROCEDURES:
Why is it important for the string and the spring to be horizontal and collinear?
It is important so that there are no components of either force acting on the bob. This allows us to relate the weight of the hanging mass directly to the force of the spring. Is there any change in the force of the spring if the bob’s mass changes? A change in the bob’s mass will not affect the force of the spring because the bob’s weight is a force that acts only along the y-axis. This is another reason why it is important to have the string and the spring horizontal and collinear. How does the force change when the mass of the bob changes? It doesn’t.

How has the velocity changed?
If the mass is larger the velocity is slower and if the mass is smaller, then the velocity is faster.
How does the centripetal force change with radius?
The centripetal force is greater with a larger radius and the force is smaller with a smaller radius. DATA:
Table One: Calibration of the Spring Force
Experimental Data| Calculations|
Mass ofBob (kg)| Radius (Lengthfrom center of Bob to center of Rod) (m)| Hanging masses, mH(kg)| Hanging Weight, mHg(N)| Force of Spring for this Radius.| .3594| 14|...