National 5 Physics 2018-19

Original post by Vladimir Poutine

Sorry, I’ve got another question.

I think I know the method for this as v = f x lambda, substituting in the 20, but the answer in the marking scheme claims A, while I’m getting 17 (D). Does anyone know why it is x10-3?

This is from the Hodder Gibson model paper.

You wouldn’t substitute 20 in you substitute 20x10^3 (20kHz) because to get the shortest wave length you want the highest frequency. Thus you do v = f x lambda, sub in the 34 and the 20x10^3 and get the answer as 0.017

Reply 83

Should say sub in 340 sorry not 34

Reply 84

OliveAgnes

6

So the velocity of sound in air is 340m/s. If the frequency increases, the wavelength decreases (so the velocity remains at 340m/s). Therefore, the shortest wavelength the student can hear will be at the highest frequency they can hear (20kHz).
340/20000(kHz to Hz) = 0.017m
Hope that explained it! :smile:

Original post by Vladimir Poutine

Sorry, I’ve got another question.

I think I know the method for this as v = f x lambda, substituting in the 20, but the answer in the marking scheme claims A, while I’m getting 17 (D). Does anyone know why it is x10-3?

This is from the Hodder Gibson model paper.

Reply 85

CharG3

12

20kHz = 20000Hz
340/20000= 0.017 mabey?

Reply 86

scott23434

Has anyone got any advice for answering explain voltage dividers. I've tried to revise them as much as possible but didnt want to use too much time.

Reply 87

Original post by scott23434

Has anyone got any advice for answering explain voltage dividers. I've tried to revise them as much as possible but didnt want to use too much time.

If you send an example I could explain how I would answer if (if I’m able to hahah)

Reply 88

scott23434

Thanks ive figured it out (I think) , goodluck tomorrow

Original post by beth1709

If you send an example I could explain how I would answer if (if I’m able to hahah)

Hope the exam goes well tomorrow for you all! :smile:

Reply 90

Who's ready for Physics tomorrow? Let's hope the Electricity part of the paper (usually worth between 10-15 marks) is generous lol.

Reply 91

Original post by Strelzo

Who's ready for Physics tomorrow? Let's hope the Electricity part of the paper (usually worth between 10-15 marks) is generous lol.

I have mixed emotions about it, part of my thinks I’ll be totally fine and I’m just overthinking and then the other part of me thinks they’ll ask awful questions and I’ll **** it up

Reply 92

Original post by beth1709

I have mixed emotions about it, part of my thinks I’ll be totally fine and I’m just overthinking and then the other part of me thinks they’ll ask awful questions and I’ll **** it up

If it's as easy as what the Chemistry paper was, we'll be flying. However it's Physics; will be a lot or problem solving questions/justification questions.

Reply 93

Original post by Strelzo

If it's as easy as what the Chemistry paper was, we'll be flying. However it's Physics; will be a lot or problem solving questions/justification questions.

True, fingers crossed

Reply 94

Original post by beth1709

True, fingers crossed

🤞🤞🤞

Reply 95

daymeetsnight

10

Original post by ellamarshall

Yes, I'm so nervous but have done quite a lot of revision, so hopefully I will be ok. This is my last exam too!!!

Tomorrow's my last exam too! I've studied alot, I've had a tutor but I've just not been able to study during my other exams (Past 3 weeks) so I feel like I've forgotten everything. Hoping it'll be okay and that my assignment was good enough to score me some points.

Reply 96

My last exam is the 22nd of May then I have 2 weeks off; ya belter lol. I'm jealous, because youse get like 3 weeks off hehe.

Original post by daymeetsnight

Tomorrow's my last exam too! I've studied alot, I've had a tutor but I've just not been able to study during my other exams (Past 3 weeks) so I feel like I've forgotten everything. Hoping it'll be okay and that my assignment was good enough to score me some points.

Reply 97

tomctutor

Original post by OliveAgnes

Would anyone be able to explain the attached questions for me? Just the method for doing them. The answer for 16 is C and the answer for 19 is E (from the 2015 paper). I'm sure they're simple things, just can't get my head around them! Thanks :biggrin:

C. 125000N

Because

E_w = F\times d

where the force is the force required to overcome friction.
Here the friction force is equal and opposite to the driving force
which is produced by the engine (unbalanced force= 0, since constant

v

).

(by the way the power of the engine is

P= F\times v

just in case it may come up!

(edited 4 years ago)

Reply 98

rittajmoghal29

10

I don't feel prepared, I have fared well in exams but I am not sure now. I just hope it's as good as Chemistry's
Thursday is my last exam woohoo! 😝💃💃
Best of luck guys, let's smash it out there, I feel weak in space and vectors. Hope there is an open ended question on ionising radiation 😌

Reply 99