IB Physics Help

Hey there, I don’t actually know when you sent this in (only just coming round to ‘resurrecting’ this blog) and I hope it’s not too late for an answer.

I may be a bit biased in not finding the maths in IB physics challenging at all in part because I also took HL maths.

Honestly, the vast majority of the maths comes in rearranging and substituting. Beyond that, you’d need to be familiar with basic trig (sin/cos waves, this is especially useful in topics that cover oscillation and circular motion), and a bit of calculus to be able to derive equations with respect to time.

Stands to reason that my followers are well into uni at this point too. That said, I still receive questions periodically so the blog’s clearly still coming up on current IBers’ searches, and I guess I’ll come back to try and help out whenever I can. This obviously also depends on my ability to recall the IB Physics syllabus, but so far I’ve not run into issues.

It’s just funny to see a page that I ran as a stressed out teen develop into a side-hobby for someone who’s going into a job interview this week at an asset management firm as a software developer.

Don’t apologise! We’ve all got to learn from scratch at some point.

u = 0 m/s, t = 3s, v = 29.4 m/s

Your unknown is s for the first question. Carrying on from my last post, the appropriate equation here is (1):

s = ½ × (v+u) × t

Incidentally, the bit I’ve bolded/italicised above (½ × (v+u)) is the expression for the average velocity. The ‘why’ becomes clear when you realise that this is an equation for distance, and the bolded expression is what we get when we divide by time, and of course distance/time = speed. Except since speed is constantly changing (due to acceleration), the value that the expression results in is an average. I’ll explain this further below the cut.

Anyway,

s = ½ × (29.4) × 3s = 44.1 mAverage speed is just dividing that by 3 seconds (how long its been travelling), and that gives 14.7 m/s.

Hi there,

This is a ‘suvat’ equation problem. As a general rule I would always recommend having all the suvat equations on hand so you can know which one to use based on your givens and unknowns: (Please excuse weird brackets; it’s the best way to communicate fractions over plaintext.)

s = ½ × (v+u) × t

v = u + at

s = ut + (½ × at2)

v2 = u2 + 2as

s = vt - (½ × at2)

Your unknown is t, and your givens are s, a, and u (u, initial velocity, is 0 because you’re dropping it, not chucking it with force.)

The appropriate equation is therefore (3).

s = ut + (½ × at2)

Since u is 0, ut is also 0. Hence:

(½ × at2) = s0.81t2 = 0.9t2 = 0.9/0.81t = sqrt(0.9/0.81)t = 1.05 seconds (to 2 decimal places)

If it was a mark off then definitely have it reevaluated if the obscene price of getting that done is not an issue

Thanks! I phoned them today and they did little else apart from reinstate the importance of those requirements. Discouraging. Trying my luck with an email backed by staff from school rn. Time to play the wait game like never before

SLs are sat in year 1 where you are? Odd but makes a lot of sense to clear up your exam schedule the following year. Might not be great with an Ab Initio language but apart from that, seems clever to me.

TBH although the physics boundaries were adjusted the entire thing was so erratic and can’t account for things like students underperforming even more than the test’s difficulty would warrant due to shock/stress/etc. Prior to that crapshoot I was aiming for no less than a 7 in HL Physics but walking out of that exam that goal lowered to 4+ because I blanked out. Consider a 5 as evidence that it didn’t bog you down too much

Considering how low my standards went after physics I was OK with my result today. Getting my EE remarked because if I get 1 more point on it, I would end up with 40/45 on my diploma.

That said I still didn’t fulfil one of my offer conditions and I’ve been agitated about it all day. Don’t know what to do to prevent rejection from the uni

My HLs were maths, physics, computer science, and ITGS. I’ve not done chemistry but I have a number of friends who did both physics and chemistry, most of whom agree that physics is the more strenuous of the two.

Walking out of this year’s physics exam, I regretted not taking SL when I could easily make the switch since I already had another 3 HLs. That’s a bold statement considering physics was one of the 2 classes I enjoyed most over the 2 years (and indeed, entertainment is why I did physics at all; I’m not pursuing it as a career later on.)

That said, the IB is aware of the difficulty of this year’s physics paper. They acknowledged it in a not-so-reassuring Twitter post. I doubt they would make the same mistake of screwing up the next cohort; I already know of honestly capable prospective physics majors who have lost or are at risk of losing their university placements.

Candle + TV = rainbow. Simple Bragg's scattering setup https://t.co/OMe9Dx4lkA

Here’s a petition I’ve been asked to share multiple times.

I completely get it, the HL paper didn’t have any mercy either.

I don’t know about TZ1, but paper 2 made paper 1 look like a godsend in comparison, but looking at it objectively I still think paper 1 was still tough.

I know how disheartening that was. I don’t think these papers negate how much work you’ve put into it; it’s clear we were all screwed over. I haven’t heard a single “That went OK.” thus far and I’ve been talking to hundreds of people about it since

Paper 2 is worth 34% of the overall mark for HL, and 40% for SL. The IA gives you a great head start, I got a 7 as well and with paper 3 I think a 4 is definitely doable. Hell, I was aiming for a 7 overall and I’m still trying after the wreckage yesterday, even though I’ve calculated that it’ll mean I need at least 55/60 on Monday. And that’s with last year’s boundaries, i.e. that’s unadjusted for whatever IB will do in July to compensate for the crapshoot of an exam we had.