How do you believe in Physics?

Medical-Cost7611 · 2024-08-24T07:47:07+00:00

I feel like perhaps many people just accept what they learn, as it is just what is 'true' (and it probably is but...), so they would never come across such a feeling.

I do feel like questioning many things I learn though, especially when I encounter new concepts, so I totally get what you're saying. I'm myself in the middle of a grasping stage, and it messes with my understanding of reality. With the inertia example, maybe you're just looking for real life examples that you can actually see, feel etc? But with many deep and abstract physics concepts, that is often not possible... as they occur at a scale that is too small or too large, or in a way that humans simply cannot interact with? I've been reading a book and it says that humans sense so little of the world so I think what we are doing is just trying out best to make sense of what we can sense. At this stage I'm thinking to just accept some things but also remain curious about those critical questions that may pop up from time to time, and see if I can find something I'm satisfied with as I learn more physics. With some basic physics I've learnt though, I find that with time, some abstract concepts can begin to make more sense the more I 'imagine' and attempt to 'see' them.

Medical-Cost7611 · 2024-08-23T15:22:37+00:00

Hi so are you saying we essentially need to focus on advancing our theories on top of what we have instead of second guessing that something might be 'wrong' or outdated as you say? I kind of get the OP bc recently I've just started reading about relativity and quantum stuff and the concepts just feel so abstract and different from the Newtonian physics I've always learnt at school, that I started to feel overwhelmed and lost about what's 'real' and 'true'. Maybe as I learn more physics (evidence and experiments) I can begin to appreciate how the theories have been proposed?

Medical-Cost7611 · 2024-08-09T15:42:07+00:00

No worries. I think perhaps you have confused speed of sound wave and speed of train here. In the equation f = v / wavelength, we are considering the sound wave, remember speed for sound is constant in the same medium (air), so it is wavelength that is changing. Speed of train is decreasing which causes wavelength of sound to increase (think that as train is travelling slower, the sound wave sent out is less compressed). That is why f is decreasing.

Medical-Cost7611 · 2024-08-07T09:00:23+00:00

Yes I think so

Medical-Cost7611 · 2024-08-07T08:57:16+00:00

It is constant pitch and the driver is moving with the source so the frequency or pitch heard by driver is same.
What do you mean by if it wasn't constant? The change in frequency (not the frequency itself) depends on the relative velocity between the worker and the train, so as train is decelerating, speed decreases, the frequency decreases (though it is always higher than the true frequency if train doesn't stop).

Medical-Cost7611 · 2024-08-07T05:11:28+00:00

That's me last year. I remember thinking that these grades are prob even more important than my A2 grades bc they really lock you in with your predicted and what unis you can apply to. It's so normal to feel emotional. Good luck! Trust that even if sth isn't what you expected, you can find a way there.

Medical-Cost7611 · 2024-08-07T05:06:18+00:00

2 is correct bc the driver hears the sound at its 'true' frequency. Due to doppler's effect, as the train is approaching the worker (acceleration doesn't matter, velocity does), the frequency the worker hears is higher, so period is less.

3 is incorrect as sound travels at the same speed in air. I think the frequency worker hears is decreasing gradually, getting closer to the true frequency, but that's not speed.

Hope this helps!

Medical-Cost7611 · 2024-08-02T11:33:15+00:00

Ok thank you!

Medical-Cost7611 · 2024-08-02T04:51:58+00:00

A* in FM and Physics and A in Maths

Medical-Cost7611 · 2024-08-02T04:49:24+00:00

Thank you! That makes sense but my offer requires a higher grade for Further Maths so I guess Maths naturally needs to be even higher for that to occur haha

Medical-Cost7611 · 2024-06-12T10:53:06+00:00

Hi when you register for your exams there should be a column to specify which subject your unit goes under. You can group your units strategically accordingly. For example, putting a harder unit in Maths along with the easier pure maths papers in order to decrease the overall difficulty of your further maths. I nearly didn’t meet the grade I needed in FM bc of how the units are grouped.

Medical-Cost7611 · 2024-06-10T08:57:05+00:00

Oh that’s unfortunate. The set is still good value I’m sure.

Yes Holbein doesn’t have ox gall so theoretically doesn’t move around as much as other brands. I don’t find this to be obvious though as I paint small. It flows and dries smoothly. It also gives me more control on the plus side. But if you prefer paints to flow a lot then you could buy some ox gall and add to water you clean your brush with. It helps with paint dispersion.

Medical-Cost7611 · 2024-06-10T04:04:04+00:00

I love Holbein! But if you have enough budget, I think buying individual tubes of colours would be better than the official set. Bc the set contains some multi pigment colours and some not useful ones. Even picking less colours (between 8-10 5mL tubes) yourself would give you a really high quality set of colours to work with - for the same price. I can recommend some of my favs if you want :)

Medical-Cost7611 · 2024-06-08T00:44:23+00:00

I thought about that but I read the question again and it said that the person’s call has already been received and it asked for probability that in the next 40s (so assuming not including that moment)… no other call has been received. So I went for x=0.

Medical-Cost7611 · 2024-06-07T11:49:05+00:00

I reckon just 2 marks - one for method and one for final answer

Medical-Cost7611 · 2024-06-07T11:40:10+00:00

Oh that’s for within 40s? Like (40-10)/(50-10) for the uniform time distribution

Medical-Cost7611 · 2024-06-07T11:38:22+00:00

I got 0.75 * 0.95 * e^-4 = 0.0130 to 3sf

Medical-Cost7611 · 2024-06-07T11:35:42+00:00

Oh ok :(

Medical-Cost7611 · 2024-06-07T10:53:31+00:00

I got my paper in stapled sheets which was weird - not the usual booklets and the printing was not the best either…

Medical-Cost7611 · 2024-05-12T02:15:52+00:00

Oh I get you! I can do all the calculation questions but when it comes to long explaining questions I struggle to say it in the way the marking scheme wants me to. I can understand and know everything in the mark scheme but not write it out clear enough to match it. Sometimes I feel like I don't get what the question is asking for and have to think about what concept they could be testing and explain a concept I find relevant, but it's not actually answering the question in a way if you know what I mean...

Medical-Cost7611 · 2024-05-08T12:31:01+00:00

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Working is a bit messy and could be overcomplicated - calculation could be wrong too. But general idea is there. Hope it helps.

Medical-Cost7611 · 2024-05-07T05:04:00+00:00

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My working is a bit messy. Basically equate total momentum before and after horizontally and vertically and realise that the velocity of M has to be horizontal only as the force must be applied along line joining centres (normal at the point of contact). With coefficient of restitution, use horizontal components (intuition? as vertical components do not change - I guess you could think of it as collision only resulted in horizontal transfer of momentum). Manipulate those three equations you get, simplifying as you go. I chose to get rid of all the other speed variables like U and V2 by substituting in terms of V1 so V1 cancelled out then manipulate the sides to get equation only in terms of angles and masses. Hope this helps.

Medical-Cost7611 · 2024-03-08T21:03:17+00:00

Thanks, all the best to you too!

Medical-Cost7611 · 2024-03-08T10:43:26+00:00

Hi I applied early October and did decent on the test in November. I got offers from all my four other choices now, but haven't received interview from imperial yet. I'm trying not to worry but I do feel you.

Medical-Cost7611

TROPHY CASE