8.1e Ex1 MJ20 P12 Q24 Stationary Wave in Tube of Water | Superposition | CAIE A Level 9702 Physics

9702/12/M/J/20: The diagram shows an experiment to produce a stationary wave in an air column. A tuning fork, placed above the column, vibrates and produces a sound wave. The length of the air column can be varied by altering the volume of the water in the tube.

The tube is filled and then water is allowed to run out of it. The first two stationary waves occur
when the air column lengths are 0.14 m and 0.42 m. What is the wavelength of the sound wave? #9702s20p12 #ASsuperpositionP1 #ASstationaryWavesP1 #Lv2

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[greensponge]

Technically you could also just use the information from the first standing wave formed, l = λ/4. The length was 0.14 m so 0.14 x 4 = 0.56 m

[pobo]

Thank you so much. I've honestly been so confused of this question, kept looking for videos online to explain, but didn't understand any of them. You explained it so well & it's so easy to understand. I really appreciate what you're doing. You saved a stressed out student with this video lol. Much Love<3

[codenepal]

It's doable by another method and i think easiest one:
1).Add up all the waves length=w/2+w/4=(3/4)w
2.As we add all the wave length give the actual length value(max value of length)
l=(3/4)w
(0.42*4)/3=w
w=0.56

[linaabdelshafy]

this is very scary i actually just fell in this question rn and this is the first thing that came up to me in

[linaabdelshafy]

but i love u so much thank u for explaining a whole lesson in 4 mins

[just_an_island_girl]

why is the difference half a wave length though ? how do we know for sure that it is half a wave length and not 1.5 or 2.5 difference ?

[AnjaniFernando]

Guy theirs easy way
Water in the tap is half wave length so
Wavelength /2 =0.42 -0.14
Subject wavelength =( 0.42-0.14 )*2 =0.56