Levitation of thin pieces of metal
using a standing ultrasonic wave
Suzuki NaomichiTanaka Takahiro
It is a sound over 20,000 H z Short wavelength
Big amplitude.
First, “what is an ultrasonic wave? ”
① Wave
② Remains in a constant position
③ Most vibrates ・・・ anti-node
Doesn’t vibrates ・・・ node ④Anti-node ~ Node ・・・ ¼ wavelength Node ~ Node ・・・ ½ wavelength
“What is a standing wave ? ”
The purpose of our experiment
To find out where objects will levitate if their thickness
changes !!
HypothesisPosition of pieces is proportional
to the thickness of it.
①mg + P↓×S =P↑×S ②Ⅴ=S d
③ρV g = mgⅤ: Volume of aluminum foild : Thickness of aluminum
foilρ: Density of air
ρdg+P ↓ =P ↑
Using the formula for acoustic
velocity
V=fλ V=331.6+0.6t V : Acoustic velocity (m/s) f : Pitch (Hz) λ: Wavelength (m) t : Temperature (℃ or )
( m ) = 8.5(mm)
anti-node ~ node 1/4λ≒2.13(mm)
node ~ node 1/2λ≒4.25(mm)
We can calculate the theoretical
levitation position from this value!!
Weight will double
Thickness of aluminum foil
doubles
the distance from the node will also double ?
Our expectation
The way of our experiment
Levitating pieces of aluminum foil with different thickness (11μm, 26μm)
Observe the position where they float
We compared them with the node position we calculated
We investigated their error
Our result
1.5 2 2.5 3 3.5 4 4.5 5 5.50
1
2
3
4
5
6
7
8
9
10
(mm) The length of one side of aluminum foil
In the case of 11μm
The length of one side of aluminum foil(mm) 2.00 3.00 4.00 5.00The different from a calculated value⊿ x(mm) 2.2063 1.8508 1.1793 1.9204
Standard deviation 0.1313 0.4164 0.1183 0.7172
1.5 2 2.5 3 3.5 4 4.5 5 5.50
1
2
3
4
5
6
7
8
9
10
(mm) The length of one side of aluminum foil
In the case of 26μm
Hypothesis
The length of one side of aluminum foil(mm) 2.00 3.00 4.00 5.00The different from a calculated value⊿x(mm) 1.9769 1.7183 1.6225 2.3250
Standard deviation 0.4167 0.4629 0.4104 0.6050
Consideration of our experiment
・ Floating position ⇒node ? or anti-node ?
・ In the case of 11μm ≒ in the case of 26μm
Not related to the
thickness of the foil !!
Our future subjects
・ Increasing the sample size of our experiment
・ Thinking about why there is no difference between the 26 micrometer foil
andthe 11 micrometer foil
Thank you for listening!