Mini Lab: What really affects angular frequency?
(For pendulums)
In this simulation, you will discover what affects the
angular frequency of a simple pendulum.
Please go to this pHet site:
https://phet.colorado.edu/sims/html/pendulumlab/latest/pendulum-lab_en.html
Click Lab.
Part 1: Finding the periods (T) with respect to Length of
String.
Please leave everything as it.
We are going to “pull” the hooked mass by 100.
1) Please find the time for 10 complete oscillations =
____________________seconds.
2) Change the mass to 1.5 kg. Again, “pull” the hooked
mass by 100. Please find the time for 10 complete
oscillations = _____________________ seconds.
3) Does the magnitude of the mass affect T? You can see
how this is different from the Mass-Spring system.
What affects the T then? (Essentially, what affects ω?)
4) Complete the table below:
Angle (0)
Length
(m)
10
10
10
10
10
0.4
0.6
0.8
1.0
1.2
√𝐿
(√𝑚)
Time for T (seconds)
10 cycles
(sec)
5) Insert a graph from Desmos (y-axis = Period (T), sec
and x-axis = Length, meters). Is this a straight line or
curve? What kind of relationship exists between T and L?
6) Insert a graph from Desmos (y-axis = Period (T), sec
and x-axis = √Length, √meters). Is this a straight line or
curve? What kind of relationship exists between T and
√𝐿?
Part 2: Relationship of T to “L” and “g”
1) Find the slope of the second graph and give me the
units as well = __________________ and units = _______
2) What kind of value can give us the units above???
What are the units for √𝑔? _________
What are the units for
1
√𝑔
? __________
3) Can you figure out what the slope of
T
√𝐿
is equal to?
4) Please clearly show how you can calculate “g” from
your slope value. Include units and a literal equation.
*5) Predict the Period of oscillation if the length of the
string of a simple pendulum = 1 meter and the pendulum
was taken to a height of 100,000 meters above the Earth’s
surface. Show your calculations neatly!
After your prediction, go back to the simulation and
change the parameters.
Find the time for 10 cycles = _____________ seconds
Find the time for 1 period (T) = _______________ sec