Time stamps: Q1 - probability tree, conditional probability (marble bags) Q2 - box plot, quartiles, large data set 12:00 Q3 - product moment correlation, hypothesis testing, 23:00 Q4 - binomial distribution, large data set (cloud cover) 29:45 Q5 - normal distribution, finding unknown SD, difference of means test 39:20 Q6 - acceleration and position given velocity vector 54:38 Q7 - particles in motion, find time given acceleration, velocity at t=0, and direction 59:25 Q8 - statics, pulley mechanics 1:06:14 Q9 - statics, ramp resting on a drum 1:20:26 Q10 - projectiles, two balls projected at angles 1:36:00
Thanks for these videos. I was teaching in schools until I left, in 1989, so am a bit rusty, but one of my grandchildren took this exam last year, found it difficult, esp. Paper 1, but she still got an A. I'm helping the younger one now, taking exam next year (assume), and these are a good check on my working. I wish I knew why they all dislike doing mechanics though.
Hi, for mechanics Q1 (b) is the displacement found displacement from the origin rather than from the original starting postiion? surely if it were the latter you would subtract the starting postion so therefore you would just ignore c because you'd be adding then subtracting it. THank you very much for this video!
The question actually says “find the position vector” which is always from the origin. You’re correct if it said find the displacement it would be a different answer
Hi @Maths Explained, is there any chance you could link and do a walkthrough of the 2020 alevel mock papers? Been really wanting to do them but cant find them anywhere? Many thanks!
@Sanad Twigiri I think it was on reddit someone was asking for the mock set 2 papers but I never knew what the heck they were but someone said they are locked for assessment purposes so only teachers can access
They only give an overall mark for the three papers combined. and for A* you needed 217/300. here is the document with all the grade boundaries: qualifications.pearson.com/content/dam/pdf/Support/Grade-boundaries/A-level/gce-subject-grade-boundaries.pdf
So I guess what you are asking is to leave it in the form 17.32i -9.6j or something similar. Generally the question will differentiate between "velocity vector" and "velocity". If asking for the velocity, you need to give the speed (modulus) and direction.
I've just done question 5 on the mechanics paper without the video and managed to use the same method as the mark scheme. BUT for part B using u sin theta/ 2ucos theta =(10/(50-40root30) I get a negative value for theta. Can you explain please?
@@mathonify Thank you. As it happens I meant to write 40 root 3 however, on checking my work I realised I had done worked out 20t cos 30 (when t = 20) as 40 root 3 instead of 20 root 3. When it was 20 root 3 everything worked out well. I would not have spotted that mistake without your help so thank you very much.
Tricky question to answer in a comment. It's quite easy to explain graphically if you draw out a normal dist. Look at the percentage. If it's greater than 50% it will be positive, if less than 50% it's negative. In the question we get P(X
Also I should mention that you can always just use a positive z-score if you always take the positive difference between the mean and x value. This is possibly how you learned it. The negative z-score is sort of an unnecessary detail, and now I think about it probably just made it more complicated than it needed to be.
I really do not understand wtf is going on with the Standard Error and why we're using it. Looks like that last question is just a copy up of the mark scheme ):
The normal distribution and standard error are not difficult topics but it’s not something you can learn from doing one exam question. Sorry if that didn’t make sense to you. Once you learn about the topic “sampling distribution of the sample means” that question is not complicated. I would suggest searching that topic on RUclips or look it up in a textbook.
I really don't know why u exist, ur only post is you kicking a baby and doomfist, this man put time and effort into his video your videos are terrible and pointless, please cry more and uninstall fortnite
@@alexolvr7534 I really don't know why u exist, ur only post is some trash csgo montage, this man put time and effort into his video your videos are terrible and pointless, please cry more and uninstall fortnite
You have 8 coins in a bag. 3 of them are unfair in that they have a 60% chance of coming up heads when flipped(the rest are fair coins). You randomly choose two coins from the bag and flip each of them 1 time. What is the percent probability of getting 2 heads? Man, please help
@@mathonify Exactly! A friend of mine just complicates it in a way so that none of us can solve it now, lol. I will also be very grateful if you will send me your version of the solution on email, so that i can decompose it: edmarrxxx@gmail.com Thanks for the answer^.^
Time stamps:
Q1 - probability tree, conditional probability (marble bags)
Q2 - box plot, quartiles, large data set 12:00
Q3 - product moment correlation, hypothesis testing, 23:00
Q4 - binomial distribution, large data set (cloud cover) 29:45
Q5 - normal distribution, finding unknown SD, difference of means test 39:20
Q6 - acceleration and position given velocity vector 54:38
Q7 - particles in motion, find time given acceleration, velocity at t=0, and direction 59:25
Q8 - statics, pulley mechanics 1:06:14
Q9 - statics, ramp resting on a drum 1:20:26
Q10 - projectiles, two balls projected at angles 1:36:00
The confidence this guy has to not make rounding errors using just 2 decimal places every calculation is what I need in my life
Haha, can't believe he actually googled how to pronounce Leuchars 😂😂 what a legend !!
I don't know how to pronounce it either!
Thanks for these videos. I was teaching in schools until I left, in 1989, so am a bit rusty, but one of my grandchildren took this exam last year, found it difficult, esp. Paper 1, but she still got an A. I'm helping the younger one now, taking exam next year (assume), and these are a good check on my working. I wish I knew why they all dislike doing mechanics though.
this guy has honestly saved my maths a level
1:06:16 Yes, doing that type of question is way easier than doing projectiles OR moments at an angle !
Do the mock papers please
Hi, for mechanics Q1 (b) is the displacement found displacement from the origin rather than from the original starting postiion? surely if it were the latter you would subtract the starting postion so therefore you would just ignore c because you'd be adding then subtracting it. THank you very much for this video!
The question actually says “find the position vector” which is always from the origin. You’re correct if it said find the displacement it would be a different answer
Thank you very much!
Hi @Maths Explained, is there any chance you could link and do a walkthrough of the 2020 alevel mock papers? Been really wanting to do them but cant find them anywhere? Many thanks!
there is a 2020?
@@livyaxx8203 yeah set of mock papers made by edexcel in january.
@Sanad Twigiri Dont have a link as I ain't done them yet, I dont know how u get them, probably need to ask a teacher
@Sanad Twigiri I think it was on reddit someone was asking for the mock set 2 papers but I never knew what the heck they were but someone said they are locked for assessment purposes so only teachers can access
Will you do exam papers for 2020?
How come edexcel 2019 exam papers have not been released yet....
because they wanna charge us for it
@@hoverton6541 Lol nah been a long time since I commented but I guess it is cuz of the autumn exams
Could you do the 2019 gcse papers please?
Are they now doing stats and mechanics in separate papers for AS level aswell?
can you guys list the 2019 new spec pure papers back as i cant find it
You are the GOAT
hey mate do you know what the a* grade boundary was for each of these papers? reguards
They only give an overall mark for the three papers combined. and for A* you needed 217/300. here is the document with all the grade boundaries: qualifications.pearson.com/content/dam/pdf/Support/Grade-boundaries/A-level/gce-subject-grade-boundaries.pdf
I think it was 74 for paper 1, 68 for paper 2 and 75 for paper 3 for an A*
For question 10, it asks for the velocity, why can't you just leave it in vector form? Doesn't taking the modulus of V give the speed?
So I guess what you are asking is to leave it in the form 17.32i -9.6j or something similar. Generally the question will differentiate between "velocity vector" and "velocity". If asking for the velocity, you need to give the speed (modulus) and direction.
I would lake a paper copy of the exam before watching the video. I can only see the statistics bit. Any ide where to find the mechanics half? Thanks
it should be linked in the description. Make sure to click "show more" in the description to see the links
@@mathonify Thanks. Never thought to do that.
I've just done question 5 on the mechanics paper without the video and managed to use the same method as the mark scheme. BUT for part B using u sin theta/ 2ucos theta =(10/(50-40root30) I get a negative value for theta. Can you explain please?
should that be cos(30) not root(30)?
@@mathonify Thank you. As it happens I meant to write 40 root 3 however, on checking my work I realised I had done worked out 20t cos 30 (when t = 20) as 40 root 3 instead of 20 root 3. When it was 20 root 3 everything worked out well. I would not have spotted that mistake without your help so thank you very much.
glad to help!
15:21 you have put the max air temp at 32.3 when it should be 32.5 man
True. Must have gone blind
@@mathonify thanks for the videos man, helped me through my mocks so good
from Q5a) the z- value for 15% , how do i know if it's negative or not if i use the data given from data booklet?
Tricky question to answer in a comment. It's quite easy to explain graphically if you draw out a normal dist. Look at the percentage. If it's greater than 50% it will be positive, if less than 50% it's negative. In the question we get P(X
Also I should mention that you can always just use a positive z-score if you always take the positive difference between the mean and x value. This is possibly how you learned it. The negative z-score is sort of an unnecessary detail, and now I think about it probably just made it more complicated than it needed to be.
how do they know its jun to oct data set.
I assume you are asking about Q2 (b). The large data set only has measurements from May-October in any year.
I really do not understand wtf is going on with the Standard Error and why we're using it. Looks like that last question is just a copy up of the mark scheme ):
The normal distribution and standard error are not difficult topics but it’s not something you can learn from doing one exam question. Sorry if that didn’t make sense to you. Once you learn about the topic “sampling distribution of the sample means” that question is not complicated. I would suggest searching that topic on RUclips or look it up in a textbook.
I really don't know why u exist, ur only post is you kicking a baby and doomfist, this man put time and effort into his video your videos are terrible and pointless, please cry more and uninstall fortnite
@@alexolvr7534 I really don't know why u exist, ur only post is some trash csgo montage, this man put time and effort into his video your videos are terrible and pointless, please cry more and uninstall fortnite
Whixh software do u use
notability
Quite a poor chiice to split the paper in 2 booklets, instead of keeping all questions in one....Oh well....
You have 8 coins in a bag. 3 of them are unfair in that they have a 60% chance of coming up heads when flipped(the rest are fair coins). You randomly choose two coins from the bag and flip each of them 1 time. What is the percent probability of getting 2 heads?
Man, please help
I get a final answer of 28.9%? This is a variation on a Kahn Academy video question I think?
@@mathonify
Exactly!
A friend of mine just complicates it in a way so that none of us can solve it now, lol.
I will also be very grateful if you will send me your version of the solution on email, so that i can decompose it: edmarrxxx@gmail.com
Thanks for the answer^.^
I might go through it in a video, and then everyone can fact check it?
@@mathonify
You really asking me?
Sure thing, thats even better:3
I cant see how this is doable in 1 hour, as stats needs 1 hour to do. Hes taking like 2 hours to do.
This is the stats & mechanics paper. Not just stats.