Lab2
Lab 2: Simple Pendulum
XXXXXXXXXXName:
Objectives:
1. To measure the period (T) of a simple pendulum.
2. To determine the effect of mass (m) on the period (T) of a simple pendulum.
3. To determine the effect of initial amplitude (o) on the period (T) of a simple pendulum.
4. To determine the effect of length (L) on the period (T) of a simple pendulum.
Lab Simulation
https:
phet.colorado.edu/en/simulation/pendulum-la
Theory
The period T of a simple pendulum, for small amplitude oscillations, is given by
where L is the length of the simple pendulum, and g is the local acceleration of gravity.
In a controlled experiment, you fix all other variables but the one of interest, in order to see the effect of that one variable on a certain physical quantity.
The dependent variable period (T) of a simple pendulum can depend on three
independent variables: mass (m), amplitude (o), and length (L). So, the period of a simple pendulum can be expressed as a function of mass, amplitude, and length,
T = T(m,o, L) .
By successively fixing all other variables but one, we can study the dependence of
the period (T) of a simple pendulum on each of the three independent variables,
T = T(m), T = T(o), and T = T(L).
The following tables are used for exactly that purpose.
Procedure:
· Click on the Intro window of lab simulation link.
· Click on Stopwatch. Make sure that speed is set to Normal (radio button) and Friction (slider) is set to None.
· Throughout the experiment, do not increase the Amplitude beyond 30 degrees.
· Choose Earth in Gravity window for Parts A, B and C.
A. The effect of mass (m) on the period (T) of a simple pendulum.
Length (fixed): 0.5 m XXXXXXXXXXAmplitude (fixed): 15o
Mass (g)
PeriodTheoratical
PeriodExperimental
100
400
600
800
1000
What conclusion can you draw about T=T(m) from this data?
B. The effect of amplitude (o) on the period (T) of a simple pendulum.
Length (fixed): 0.5 m XXXXXXXXXXMass (fixed): 200g
Amplitude (o)
PeriodTheoratical
PeriodExperimental
o
T(S)
T(S)
5
10
15
20
25
30
C. The effect of length (L) on the period (T) of a simple pendulum.
Amplitude (fixed): 10o XXXXXXXXXXMass (fixed):
Length (m)
PeriodTheoratical
PeriodExperimental
Period2Experimental (S)
L(m)
T(S)
T(S)
T2(S2)
0.3
0.35
0.4
0.45
0.5
Q1. Is the effect of air resistance (drag), through the viscous fluid of air, a systematic or random e
or with regard to the period (T) of a simple pendulum?
Hint, imagine the pendulum moving through water.
Q2. Thomas Jefferson proposed using the length (L) of a simple pendulum whose period (T) was exactly 2 seconds as the definition of a standard meter. What is the length (L) of a 2 sec. pendulum in SI Units?
Q3. What is the period (Tmoon) of a Jeffersonian pendulum on the surface of the moon? Hint: Assume gmoon = (1/6)gearth, where gearth = 9.80 m/s2, and that the period of a Jeffersonian pendulum on the earth is: Tearth = 2.00 s.