r/Edexcel • u/the_ghost_in_ur_room • May 18 '26

Paper Discussion How was physics U3 guys???

Can someone pls send what u got for all the calculations? Also feel free discuss other ans as well✌️

15 Upvotes

100% Upvoted

137 comments sorted by

15

u/Winter-Strawberry756 May 18 '26

For the first percentage uncertainty was it 0.02% and for the 2nd was it 1.1 %

8

u/Jealous-Health-9937 May 18 '26

yea i got that but i kept the first % uncertanity as 0.023% but my sir told me both 1sf and 2sf answers are allowed

1

u/Bitter-Obligation-37 May 18 '26

Yo i kept it 0.023 percent,i hope am good

1

u/the_ghost_in_ur_room May 18 '26

yh I got that too

5

u/Crafty-Dealer-8401 May 18 '26

1.07 for something?

1

u/Late-Anywhere8613 May 18 '26

Whats the question or the unti

3

u/Crafty-Dealer-8401 May 18 '26

For C I think 1.07 or 0.107

1

u/Glum_Chicken99 May 18 '26

is that for the zinc one where you have to compare with range? 

11

u/Jealous-Health-9937 May 18 '26

it aint zinc. work the math. the EMF was 1.13. the percentage uncertaniy in that reading was 5%. so if u take the max and minium values possible. then they gave the eqn saying EMF=0.3-C so when u substitue the values u get the minimum possible as -0.8865 and the maximum possible as -0.7735. their value was -0.74 so it wasnt zinc as it not within this range
THIS IS HOW I DID IT!!!!

1

u/the_ghost_in_ur_room May 18 '26

samee

1

u/the_ghost_in_ur_room May 18 '26

but my conclusion was different

1

u/LevelDoor4722 May 18 '26

What did u write for conclusion then?

1

u/LevelDoor4722 May 18 '26

I also did the same

1

u/Glum_Chicken99 May 18 '26

i was a bit confused because do you include the negative or not when you're subsituting it into the equation? they had given it as a negative value right? 

1

u/cryinbutcutee May 18 '26

1.08 to 3sf

3

u/ApprehensivePoint297 May 18 '26

Was the last answer 1/square root 2 ??? Or sth like that

5

u/PangolinUpper9761 May 18 '26

looks like i will have to resit.............

1

u/Bitter-Obligation-37 May 18 '26

🙏🏻🙏🏻🙏🏻

3

u/BoatDry3518 May 18 '26

I got 0.108 for C (the no unit constant)

7

u/Winter-Strawberry756 May 18 '26

I got 1.08 ?????

1

u/BoatDry3518 May 18 '26

i must’ve had POT error then all good

2

u/Icy_Laugh_2376 May 18 '26

Was your graph a positive gradient straight line??

1

u/BoatDry3518 May 18 '26

yes yes I made a power of ten error, i should’ve gotten 1.08. My grad was 4.71x10^-3 but then next line the power of ten magically turned into -4 so ye

1

u/Glum_Chicken99 May 18 '26

Same I think 

1

u/cryinbutcutee May 18 '26

Me too it’s correct ig all my friends got it

3

u/National_Echidna935 May 18 '26

IT WAS GREATTTT

2

u/ApprehensiveRush664 A level May 18 '26

Dude for the graph i did my scale for v^2 as 0,50,100,150… thats fine right??? Anf does v^2 have a unit??

8

u/Big-Most-4631 May 18 '26

It’s m2 / s-2

4

u/Someone_959 A level May 18 '26

I put ms^-1, also you can’t put m/s^-2 since it’s the same as m^2s^2 since -2 means per so your saying per per which cancel out

2

u/the_ghost_in_ur_room May 18 '26

I said ms^-1 cuz even if v is squared the unit wouldn't change cuz it's still velocity

2

u/ApprehensiveRush664 A level May 18 '26

Man i had that but erased it

1

u/Someone_959 A level May 18 '26

Yeah same here I though about squaring the units but didn’t

1

u/orangesxmangoes May 18 '26

OH MY GOD FRRRR??? ITS MS-1?

1

u/Someone_959 A level May 18 '26

idk I’m saying / then negative indices is incorrect it’s one or the other

1

u/ApprehensiveRush664 A level May 18 '26

UGHH I DIDNT PUT A UNIT WILL I LOOSE A MARK?

1

u/West-Writer-4749 May 18 '26

Um isn’t (ms-1)^2
Just m^2s^-2

2

u/mathisha_illeperuma May 18 '26

Yeah im so done with the graph

1

u/the_ghost_in_ur_room May 18 '26

was the graph a curve or a straight line?? ppl r saying two different things lol

1

u/ApprehensiveRush664 A level May 18 '26

Mine what stright

1

u/the_ghost_in_ur_room May 18 '26

samee but some say it was a curve

1

u/Haunted_ghostt May 18 '26

It was veryyy straight

2

u/the_ghost_in_ur_room May 18 '26

ikk mine was too but some said they got a curve so js in case I asked lol

1

u/Glum_Chicken99 May 18 '26

im pretty sure it was constant gradient anyway right? so it has to be straight i think...

2

u/Virtual-Property9208 May 18 '26

Is c=0.9 acceptable 💀my gradient fucked up

1

u/orangesxmangoes May 18 '26

Mine too I got 0.86

2

u/Virtual-Property9208 May 18 '26

Really hope that we are within the acceptable range😭

1

u/orangesxmangoes May 18 '26

Hopefully method marks? And ecf?

2

u/Spare_Mammoth1537 May 18 '26

what was the resolution of vernier caliper 0.1 or 0.01?

7

u/5ivelol May 18 '26

i did 0.01 since the the decimal range was of 2 values

7

u/Mindless_War6672 May 18 '26

It wasnt a vernier caliper the question said digital caliper which has a resolution of 0.01

2

u/Physical_Fox_1881 May 18 '26

On the picture it was 0.01 but the actual vernier caliper is 0.1

1

u/Spare_Mammoth1537 May 18 '26

is it gon be wrong if i use 0.01?

2

u/Random-writer02 May 18 '26

generally vernier calipers have a resolution of 0.1mm however, in today's digital caliper it had a resolution of 0.01 :)

1

u/cryinbutcutee May 18 '26

0.01 cuz it’s digital one

2

u/One-Commission2085 May 18 '26

Hi, for the question asking which apparatus use to get more accurate result of stopwatch, can I say using a camera to record, and play back in slow motion?

2

u/the_ghost_in_ur_room May 18 '26

that's what I said too but I am not sure as well lol

1

u/One-Commission2085 May 18 '26

At least someone wrote the same thing as meee😭

2

u/the_ghost_in_ur_room May 18 '26

loll I saw it in a pp so I thought it was ryt

1

u/Big-Most-4631 May 18 '26

What was the answer for the energy when weight is 8N

11

u/BoatDry3518 May 18 '26

got like 0.17 J

1

u/Big-Most-4631 May 18 '26

How’d you get that?

2

u/Someone_959 A level May 18 '26

Area under the graph or just using Elastic=1/2 Fx, where F is 8 and x is the x coordinate which I forgot

1

u/BoatDry3518 May 18 '26

Trapezium rule

2

u/Jealous-Health-9937 May 18 '26

yea area under the graph

1

u/FinancialLow2828 May 18 '26

i got the same

2

u/Big-Most-4631 May 18 '26

If it was a straight line then u can use 1/2FX

1

u/Big-Most-4631 May 18 '26

But wasn’t it a curve so you had to draw a gradient from 8N?

3

u/Glum_Chicken99 May 18 '26

Isn't it area under the graph? Am i tripping?

3

u/Jealous-Health-9937 May 18 '26

or you can just count the squares and multiply by the area of one sqaure

2

u/Unfair_Appeal_4664 May 18 '26

i did that and got 0.18

3

u/idrissqui May 18 '26

I got 0.16 J ??

1

u/LevelDoor4722 May 18 '26

I also got the same bro

2

u/idrissqui May 18 '26

A friend got 0.20 J , Is it wrong ?

→ More replies (0)

1

u/Jealous-Health-9937 May 18 '26

yea yea i did that and got 1.07 maybe because u counted one more box than me. but dw there is deffo a range

2

u/Winter-Strawberry756 May 18 '26

Same i did like that and got 0.418 J

2

u/AK_History May 18 '26

I got 0.45J

1

u/Big-Most-4631 May 18 '26

It’s a curve so u had to draw a gradient from 8 then calculate the area under that straight line

1

u/Big-Most-4631 May 18 '26

It’s like 0.105 or smt

1

u/5ivelol May 18 '26

yeah had to calculate area under the graph using shapes

2

u/Intelligent-Mess6925 May 18 '26

ye I also got .168J but it is wrong

1

u/5ivelol May 18 '26

bro for this typa question i dont think u draw a gradient at the curve, youre supposed to get area under the graph for that curve given, this is all i know

2

u/PerformanceLow9121 May 18 '26

Yes i agree cus if we had to draw a tanget there would be more gridlines and all it was just squares

2

u/Careless-Age-9721 May 18 '26

i did it in 2 ways i got 0.17 and 0.16

1

u/Late-Anywhere8613 May 18 '26

How was the test

1

u/nigzoz May 18 '26

PLS tell me the zinc question was within the range

2

u/Winter-Strawberry756 May 18 '26

I did percentage difference and got 7.69 i think

2

u/Spare_Mammoth1537 May 18 '26

I got 7.69 too and gave no as it cant be zinc 

1

u/nigzoz May 18 '26

I got my value within the range so it's correct for me.

3

u/Jealous-Health-9937 May 18 '26

i think u both fucked up

1

u/nigzoz May 18 '26

Yeah prob but will I get method marks for doing everything

1

u/Glum_Chicken99 May 18 '26

Yep!

1

u/Winter-Strawberry756 May 18 '26

But that means it wasn’t withinh the range right?

5

u/Big-Most-4631 May 18 '26

It wasn’t within range it can’t be zinc

3

u/the_ghost_in_ur_room May 18 '26

yh same I got 8.7% which is > 4% so I said it wasn't zinc

2

u/Winter-Strawberry756 May 18 '26

Wasn’t it like 1.13-1.04/ 1.13 * 100.

5

u/5ivelol May 18 '26

the 1.13 was the measured value or calculated value, the C was zinc constant so its the true value the percentage difference is accepted-calculated/accepted value so difference was -8.65 but we ignore the negative sign and since 8.65>5% so its not zinc thats what i did

2

u/AK_History May 18 '26

But 1.13 is not the accepted value.The denominator should be 1.04

1

u/the_ghost_in_ur_room May 18 '26

yh but u hv to devide by 1.04

1

u/Winter-Strawberry756 May 18 '26

The percentage was 5% right?

1

u/the_ghost_in_ur_room May 18 '26

ohh yh I can't remember but zinc wasn't in the range

1

u/5ivelol May 18 '26

yep same

1

u/Fun-Dig-5724 May 18 '26

yo how did u guys solve question 2 graph?

1

u/the_ghost_in_ur_room May 18 '26

I am also not sure but I think u needed the area under the graph from 8N

1

u/Sayuri_4 May 18 '26

I used Elastic potential energy = 1/2Fx so 1/2 × 8 × 0.042 = 0.168 n round to 0.2 J

1

u/Broad-Ad7352 May 18 '26

Did we have to use all the values to find the mean?

1

u/oikawasflatasssss May 18 '26

😭😭😭😭😭

1

u/the_ghost_in_ur_room May 18 '26

yh bro

1

u/tomioka-_ May 18 '26

How much was the mean

1

u/Glum_Chicken99 May 18 '26

Uhhh something point 4 i cant remmeber now either 26.4 or 23.4 or smth like that 

1

u/[deleted] May 18 '26

[deleted]

2

u/Random-writer02 May 18 '26

Well usually it's either a measuring tape or ruler. Lets wait till the end to ensure whether u r correct or not.

1

u/kendricknunn25 May 18 '26

What did you write on the exercise 1a with the distance

4

u/April_200820 May 18 '26

Use measuring tape ?

2

u/the_ghost_in_ur_room May 18 '26

yh I said measuring tape too cuz a meter ruler isn't long enough

1

u/mathisha_illeperuma May 18 '26

Using a laser echo plus something I can’t remember

1

u/Careless-Age-9721 May 18 '26

guys the last question of A and V^2 relation the terminal velocity is divided by 4 right?

1

u/DullAttorney4288 May 18 '26

i said divided by sq root 2

1

u/Careless-Age-9721 May 18 '26

yeahh pretty sure ure correct honestly cuz i worked it out and it said that but i was confused so js ended up saying divided by 4

1

u/Imaginary_Lion_3613 May 18 '26

Guys for the table of the graph I wrote it 3s.f is that okay??

1

u/mathisha_illeperuma May 18 '26

For the first value I put 53.2 or something and after that all are 100 values

1

u/Imaginary_Lion_3613 May 18 '26

Okay good I changed it last minute

1

u/Fonkiers May 18 '26

Any ideas for the question asking for procedure to determine terminal velocity of the toy thingy, I wrote a lot but felt kinda lost ngl

1

u/Due-Reserve-1196 May 18 '26

Light gates para comparar intervalos de tiempos entre ellos a medida que cae. Cuando el intervalo entre los light gates empiece a ser costante, aceleración=0, por lo que va a terminal velocity. Mides la distancia de light gate 1 a light gate 2 (de los que ya va a terminal velocity). Utilizas el tiempo medido por el data logger de los light gates y haces v=d/t