In this post, we will be going to the basics of setting up the retort stand and pendulum experiment. Most probably, this will be the first experiment which you will perform in the lab. Let’s start with the setting up the retort stand, boss and the clamp.
Next we will take a look at how you set the up the apparatus for the pendulum experiment.
How is the period affected by length, mass of bob, and angle of release? Click on this post to find out more.
Click here to see how to use a digital stopwatch.
Basic Concepts of the pendulum:
Refer to this post for the factors that affect the period of the pendulum
Period, T, is the time taken for one complete oscillation.
The period T of a pendulum is affected by the following factors.
1) the length of the pendulum:
– the longer the length, the longer the period (i.e. swing slower)
2) the gravitational field strength, g
– the greater the g, the shorter the period (i.e. swing faster)
(e.g. the g on earth is 10 N/kg while that on the moon is 1.6 N/kg, hence the period on the moon will be longer)
NOTE: (common misconceptions)
Period, T, of the pendulum is NOT affected by
1) the angle of release (as long as the angle of release is between 10 to 15 degrees)
(if the angle of release is small, the swing will not be fast and air resistance will not be significant)
2) the mass of the pendulum ball
Refer to the video below for the demonstration of the above concepts.
Pendulum: Displacement-time vs KE-time graphs
Click here to understand the concepts of Displacement-time vs Kinetic Energy-time graphs of a pendulum
How to set up the pendulum experiment?
Click here to view the video
For Combined Science (Physics), drawing of vector diagram is a must.
In general, two known forces are given and the resultant force of these two forces is to be found using the vector diagram.
There are two methods to draw vector diagram 1) Parallelogram method and 2) Tip-to-tail method. In this post, the parallelogram method is used.
Click here to view another post on Closed-Loop Triangle Method (2 forces, 2 unknowns, 1 known)
Vernier caliper and micrometer screw gauge are used to measure length.
Vernier caliper is used in general for measuring length between 0 to 15 cm.
Micrometer screw gauge is used in general for measuring length between 0 to 2.5 mm.
The accuracy (precision) of
– ruler (0.1 cm)
– vernier caliper (0.01 cm)
– micrometer screw gauge (0.01 mm)