Part 1:
Constant: 20 oscillations
Distance of the string i.e. from the tied knot of the stand to the magnet = 6”
Variables: Time (seconds) and Direction (arrow) of magnet pendulum swings
In part 1 of the investigation, the magnet will be swung across constant amplitude with the constant no. of 20 oscillations. With each changing direction, the time period for the 20 oscillations will be noted down on paper. Then, the readings will allow us to deduce if the changing direction of magnet has an effect on the time period or not. Below are the four directions, named A, B, C and D along their time period readings.
Direction A: (Magnet horizontal, vibration left and right)
Direction B: (Magnet vertical, vibration up and down)
Direction C: (Magnet vertical, vibration left and right)
Direction D: (Magnet horizontal, vibration left and right)
Comparison chart for varying directions
Analysis:
As per the results of the investigation, the change in the direction of vibration of the magnet for 20 oscillations does not affect the time period of the oscillation. As we can see he comparison chart above, the values for directions A, B, C and D are almost same, with very minuscule micro second differences. The possible uncertainty here can be human error in timing the experiment and secondly, the quality of magnets i.e. minor change in size and weight. Moreover, the balance of the string attached was not at most in perfect form, hence the unnecessary rotating of the magnets from the point of tied knot must have affected the time period readings. Hence, the part 1 of the investigation comes to suggests that the change in direction of the vibration of the magnet does not affect the time period of the oscillations.
Part 2: _ Pole Combination A
Methodology: B
For Dual magnetic pendulum investigation:
-
Hang a bar magnet horizontally with the help of two strings.
- Now put another magnet just below the hanging magnet, in the same direction as the hanging magnet, with similar poles facing each others.
- Using the thread string, tied in balance with the lab stand. The thread should be strongly tied with the magnet & stand.
- Make sure the magnet is not rotating from its point of centre. This is done in order to allow precise timed readings, as the oscillation progresses smoothly.
- Change the distance between the two magnets, keeping the oscillations constant at 20 and then note the change in the time period.
- Now, vibrate the magnet (for different directions) with small amplitude, first along the length then along with width. Measure the time period of vibration. Also find the rate of decrease in the amplitude of vibration.
- Repeat 1-6 for varying direction combinations.
Note:
Readings are for vibration along the width only.
Comparison Chart for N-N to S-S pole combinations with varying distance between stationery magnet and dynamic magnet.
Analysis:
As per the results for part 2 of the investigation, we put hanged a magnet of the same size as used in part 1 of the investigation by a tied string, making it a dynamic object. Then, we placed a stationery magnet of the same size below it. As we vibrated the dynamic magnet along its width, we slightly altered the distance between the stationery magnet and the dynamic magnet to see if had affect on the oscillations’’ time period. Now, the interesting part of the investigation arises. As you can see from the comparison chart of the same pole combination of N-N to S-S, a slight change in distance between the two magnets, that is a (1.6 minus 1.0 = 0.6 cm) 0.6 cm change brings a 2.0+ second change. The increase in the distance between the two magnets increases the time period for the 20 oscillations. The theory behind this is simple. As the two magnets move closer to each other, they face a higher amount of N to N and S to S repulsion, so they are pushed with a greater force than they would be when they would be apart (as the case is for d=1.6 cm). This in result decreases the time period, as the 20 oscillations are completed in a lesser time period.
This diagram shows the repulsion of the two magnets, in the N-N & S-S pole combination.
Part 2: _ Pole Combination B
Note:
Readings are for vibration along the width only.
Note:
See the next page for Comparison Chart and Analysis
Comparison Chart for N-S to S-N pole combinations with varying distance between stationery magnet and dynamic magnet.
Comparison Chart for N-N to S-S pole combinations with varying distance between stationery magnet and dynamic magnet.
Analysis:
There is a difference between the varying pole combinations at d=1.6 cm, with a N-N to S-S pole combination magnet vibration taking +2 seconds longer than the N-S to S-N pole combination. What can be the reason behind this? Why is the N-S to S-N pole combination much quicker in terms of time period as compared to its counterpart pole combination, even at the same number of oscillations taking into consideration along with the distance between the magnets?
However, we there is one important relation that has been deduced from part 2)b) of this dual magnet investigation. At d=1.0cm, the N-N to S-S pole combinations take 16.22 seconds i.e. 1 time period for their 20 oscillations. In contrast to that, at d=1.0 cm N-S to S-N pole combinations take 16.22 seconds for the same number of oscillations. What is the physics behind this? Well, here is my interpretation:
Postulate 1:
In N-N to S-S pole combinations, the magnetic poles are repelled, which means the force of attraction is going upwards, which is against the force of attraction of earth’s gravity.
Postulate 2:
In N-S to S-N pole combinations, the magnetic poles are attracted, which means the force of attraction is going downward, which is towards the force of attraction of earth’s gravity, hence the gravitational field force assists the oscillation to be carried out at a faster pace. This in result decreases the time period.
Graphical representation of postulates:
A
B
C
Live Experiment Images
The End