Physics Pendulum Lab Essay

Jessica Vandeventer
24 February 2016
Pendulum and the Calculation of g
Purpose/Question-
The purpose of this lab is to see how mass and length effect the period of a pendulum. Hypothesis–
The bob mass will not effect the period of the pendulum, but changing the length of the pendulum sill change the period of the pendulum.
Data Tables/ Graphs –
Data Table 1. Trial Values at Varying Degrees.
Length of string: 100 cm = 1 m Mass of bob: 24 g = .024kg

Placement of Bob Degrees

Amplitude (bob horizontal displacement) cm

Trial 1 (s)
5 cycles

Trial 2 (s)
5 cycles

Trial 3 (s)
5 cycles

Avg. Time
(s)
5 cycles
Period
1 cycle
5 o
14
10.75
10.15
10.04
10.43
2.09
10 o
35
10.34
10.16
9.94
10.15
2.03
15 o
48
10.13
10.12
10.13
10.19
2.04
20 o
68
10.19

C. How did the change in length of the pendulum affect the period and frequency?
Changing the length of the pendulum effects the time of the period and frequency. As the pendulum and shortened the time it took to make a full cycle decreased.
D. What would happen if you used very large amplitudes? Check your hypothesis by trial. What amplitude did you use? What is the result?
Changing the amplitude of the pendulum will not effect the period of the pendulum. I used an amplitude of 450 and the length of 1m. The period of one cycle was 2.06, which is about the same as in data table 1.
E. Hypothesize about how a magnet placed directly under the center point would affect an iron bob? Try it and find out. Did your trial verify your hypothesis?
The magnet will slowly effect the pendulum, as long as the magnet was strong enough to catch the iron bob.
F. How close was your calculation of the value of g at your location? What might be a few sources for error in your experimental data and calculations?
All of my calculations were close to the accepted value of gravity. A few of my calculations were further off, but most were very close. Some errors would be that the timing of the pendulum swinging was off. And the length of the pendulum may have not been

What would you expect of a pendulum at a high altitude, for example on a high mountain top? What would your pendulum do under weightless conditions?
At a high altitude, the effective acceleration due to gravity will decrease. Because of this the time of the period will increase. If it were in weightless conditions it would continue to swing because there is nothing effecting the pendulum.
Claim-
If the bob mass or the amplitude on a pendulum is increased it will not effect the period of the pendulum. Changing the length of the pendulum will affect the time of the period on a pendulum.
Evidence-
As I experimented with my pendulum I discovered that the time of one period on a pendulum with bob masses of 25g and 50g and the length of the pendulum for both was one meter, the period was not effected. When I change the length of the 25g pendulum the time of the period was effected. As I decreased the length of the pendulum the time it took to complete a period was decreased.
Reflection-
My ideas did not change at all after completing this lab. I can connect this lab to how the bob mass does not effect a pendulum, but the length of the pendulum changes the