A Level Physics Revision: All of Oscillations (in under 15 minutes!)
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- čas přidán 6. 08. 2024
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Check out my Oscillations Physics Workbook: koji.to/k/9CK5
A full revision lesson on Oscillation. Here is a full playlist of online lessons:
• Oscillations
Music for the intro: www.bensound.com (thanks! )
Chapters:
00:00 Intro
00:15 Definitions
01:30 Simple Harmonic Motion
02:05 Graph of acceleration vs displacement
03:56 Experiment to find T and f
05:01 Displacement equations
07:29 Graphs
09:23 Damping
10:41 Forced Oscillations
11:24 Natural Frequency and Resonance
This is excellent A Level Physics revision for all exam boards including OCR A Level Physics, AQA A level Physics, Edexcel A Level Physics, CIA Cambridge International A Level Physics, Eduqas etc.
Hi guys! I have also filmed some past paper questions on this topic. Hope you find these helpful. Good luck with the exam prep! : )
czcams.com/video/kyKW0I4L1ZI/video.html
got my exam in about an hour and a half 💀. Good luck every1
i'm very fortunate for stumbling across your channel. Thank you very much for this excellent teaching!
Thank you very much for the kind words! Much appreciated!
the way this man has actually saved my a level
Glad the channel is helpful!
This was really helpful - thank you!
Anytime! Thanks a lot for your comment!
Great video! Thanks for the help 😎
Anytime! Glad it's helpful!
Thank you for the effort!
Anytime, thanks for the comment!
Amazing video
Thanks for such a clear explanation of the topic😊👍
Glad you liked it and you found it useful! : )
OMG THANK YOU SO MUCH you are really really helpful
Anytime! Thanks for the comment!
good content. really helps my study :D
Thanks! Glad to hear that!
It's 2024 and this video is still in the business of saving lives
I'm shsring this. Thsnks so much ✨
thank you so much! 4 years ago I made just to help my students revise and it's amazing how much it has taken off. Thank you all SO much!
i have a test tmr and this really helped me consolidate thanks:)
Thanks a lot for the comment! Good luck tomorrow!
for the shm graphs: the gradient of the displacement time graph starts at 0, but increases (as it gets steeper), until it reaches the x-axis. why in the velocity time graph does speed decrease in the start? If the gradient is increasing in steepness, and gradient = velocity, then why is it velocity starts by going downwards?
thank you for the video
You're welcome! : )
OCR GCE paper 1 in 2 days… nerve wracking!
good luck!
For OCR A how would you recommend revising for paper three, because there don't seem to be lots of topic questions on practical's out there? Also thank you so much for this video and all the other revision videos, they've been really helpful for revision for my year 13 mocks!
I reckon seek the hardest questions out of each topic and also spot some pattern - there seems to be a lot of experimental info - e.g. line of best fit, line of worst fit - explained here - czcams.com/video/bR8tW2p3AcM/video.html
I have some walkthroughs on many of the paper 3s, including this one: czcams.com/video/KHiO1qO4nRI/video.html
On circular motion for instance, you sometimes get the trickier cases - e.g. circular motion at an angle or vertical one: czcams.com/video/rlGX6YZRQ_c/video.html
Here is a tricky electric fields one too: czcams.com/video/gWQpRj5BZ2g/video.html I will be posting a lot more closer to the exams! : )
Hi! Just for better understanding, what exactly is the amplitude for a swinging pendulum - more specifically e.g. is it measured vertically or horizontally from equilibrium or perhaps even arc length?
Thanks!
Sure! It's the maximum displacement from the equilibrium (think of a vector pointing at an angle to the equilibrium).
For OCR A do you reckon we could get tested on a question using E =1/2 m*w^2*x^2 (from KE formula and v = w*r ? E.g find w using a = w^2x then find some sort of height.
Possible, you never know : )
you explained this in 15 minutes while my teacher is taking 2 weeks and still going
Just to be fair, when I teach this, I take around 2 weeks as well, but I do a ton of problems to practice and experiments. The actual theory though can be summarised very well in a short video. Thanks for the comment and glad you are finding it useful!
Hi are you planning on doing a oscillations practicals video? would be very useful fro ocr paper 3!
Hoping to do one tomorrow, paper 3 is quite different though, less about common practicals and more about the process. Will post on this tomorrow! : )
@@zhelyo_physics hi sir what do you mean by less about common practicals and more about the process?
what is damping and resonance I dont understand and my a levels tomorrow lol
Hi quick question on ocr 2018 paper 1 multiple choice q9, can you explain why the damping force is maximum at 0 displacement and why damping force is opposite to velocity but not acceleration, thanks!
Hi! I have actually filmed this question here: czcams.com/video/qazLt0PRIxQ/video.html Hope this helps!
I have a question. What causes the net force acting on the pendulum bob. Is it the horizontal component of (mg) and (T in the string) or just one of them?
precisely! The net force is always the sum of all forces.
Can you please explain the difference between degree mode and radian mode in calculators? And when to use which mode?
Sure depends on your calculator but typically there is a "mode" on your calculator for degrees or radians. Generally in oscillations unless otherwise states the x=Acos(wt) or x=Asin(wt) are the only equations that require radians
Alright thank you
@@moeezf3344 Radians are like the natural mode of degree. The degree is made by human convention by splitting a circle 360 times. The radian is literally the angle made by an arc that is exactly 1 radius length long. Since the circumference of a circle is 2π, a circle is 2π radians. Whenever you’re working with anything to do with circles or oscillations, anything with sinusoidal curves you must use (most of the time) radians. There are other reasons but that may be too complicated to explain to you aha.
Do we need to know, critical, light and heavy damping graphs?
depends on your specification, I'd remember them just in case even if they are not explicitly on, as questions on ideas such as these can still arise
@@zhelyo_physics Thanks for these videos and the reply!
the formula in the graph section, those v = delta x/delta t, how can you use it if you are only given a graph?
that's just a general formula for any velocity time graph to signify that velocity will be the gradient in an x,t graph. and acceleration will be the gradient in a v,t graph. Hope this helps!
hello, the AQA spec says we need to know, "Resonance and the effects of damping on the sharpness of resonance". just to check, it that the graph at 12:41 ? Thanks
Yep! So in short - lightly damped systems have a very sharp resonance peak, the heavier the damping the "flatter" the peak. Hope this makes sense!
@@zhelyo_physics thank you so much! You're a legend, God bless you!
May I ask what about "understand how damping and the plastic deformation of ductile materials reduce the amplitude of oscillation." work? This is in the IAL physics spec (5.5, 153)
and how does "understand how to apply conservation of energy to damped and undamped oscillating systems." work, thank you so much.
Sure! So energy is conserved in damping. The energy of oscillation is transferred into another medium, e.g. water, air, some fluid etc. With each cycle of oscillations there is less and less energy into the system, decreasing the amplitude.
@@zhelyo_physics thank you so much!
thanks.
No problem!
Hi, why does the peak shift to the left on the graph when damping is introduced?
excellent question, it's beyond the scope of the course and you don't need to know this for the exam but when a damping force is introduced, this changes the equation of motion for the system, resulting in this shift.
@@zhelyo_physics ohhh thank youu!
Hi you mentioned damping affects amplitude but not time period so how come in the resonance graph when there is damping the frequency changes? surely if time period stays the same so does frequency?
Hi, typical question would show the same frequency, indicating that the time period is constant. At least for light damping.
@@zhelyo_physics Hi sorry to bother you again but I just saw an exam question where it says the peak (on the amplitude frequency graph) for a oscillating object becomes thinner when damping is reduced, could you please explain this.
Not bothering, I like these things! So normally the effect of damping is to reduce the amplitude, but in SHM the time period is independent of the amplitude. Having said that there can be some situations I imagine in which it may be affected somehow. Can you comment with a link to the question or an exam board/paper year and question number?
@@zhelyo_physics Hi its ocr A october 2020 paper question 4 multiple choice, again thanks for the help!
@@thevinecompany7733 I know this question! So this is a question about the graph of amplitude against frequency. And it shows that the natural frequency changes and that the amplitude is lower. I actually explain this exact question at 12:59 of this video : ) The actual frequency would normally be unchanged (remember frequency = cycles per minute) and the natural frequency which changes is the frequency at which an object will vibrate after an initial disturbance. Hope this helps!
is this good for cie revision??
Yes
Shouldn't velocity be increasing as displacement is decreasing? I feel as though that graph is wrong.
Which graph exactly?
@@zhelyo_physics the one using x/t to determine v/t
Isnt acceleration proportional to the -displacement?
correct. However this is still proportional (straight line through the origin), however the constant of proportionality is negative. Hope this helps!
@@zhelyo_physics oh yes now i see, because gradient is negative then the proportionality is direct but negative this is why you watch the whole video before commenting haha
hi ZPhysics. Great content. keep it going!!!!!!!
for 7:24 i got 0.0183m.
could you clarify why you got 0.04m
edit by rewatching I'm assuming you put Asin(Wt) instead of Acos(wT)... I might be wrong for assuming.
Excellent question, I think your calculator is in degree mode, it should be in radians for this question and when using those equations.
oscillations oscillations oscillations
hi, which app do you use? thanks
Microsoft Whiteboard
sorry sir but it looks like you missed the bit on energy of a simple harmony oscillator
thanks for the comment, filmed right here: czcams.com/video/6yb13pvpOYY/video.htmlsi=ROBM6RNwGIwBNQ5b
just failed a topic test on this...
sorry to hear this! Drop a comment on any parts that you don't understand. Always happy to explain things further! Good luck you can do it!
Thanks. It was really so helpful.🥹
Anytime! Thanks a lot for the comment!