Physics: Post your doubts here!

[Thought blocker]

On a particular railway, a train driver applies the brake of the train at a yellow signal, a distance of
1.0km from a red signal, where it stops.
The maximum deceleration of the train is 0.2ms–2
.
Assuming uniform deceleration, what is the maximum safe speed of the train at the yellow signal?
A 20ms–1 B 40ms–1 C 200ms–1 D 400ms–1

A is a guess.

 

[janasalem]

yes A is the answer but how ?

 

[Thought blocker]

yes A is the answer but how ?

I am in hurry, so make two parts diagram, on from yellow to red n till brakes.. Which is asked in the question.
Its uniform deacileration so keep it same and use in the equation. You get it

 

[snowbrood]

Change in momentum = Final momentum - Initial momentum
Hence in shouldn't be -P - P = -2P?

yea u are right bro

 

[Glory Hunter]

please help asap
Thought blocker
Physicist
silver slick

 

[Glory Hunter]

explained at

http://physics-ref.blogspot.com/2014/05/physics-9702-notes-worked-solutions-for.html

Thanx a lot MAY GOD BLESS YOU

 

[marduk]

can someone give me the link to the 2014 question papers?

 

[Glory Hunter]

thanks

there are some other solved problems on projectile motion there. the question s above it.

Take a look at them. It should help

For sure your blog is epic

 

[janasalem]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s09_qp_2.pdf
variant 2 question 2 b

 

[janasalem]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s09_qp_2.pdf
variant 2 question 2 b ?

 

[janasalem]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s03_qp_1.pdf
question 7 explanation please for vertical component

 

[SIstudy]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w09_qp_32.pdf
can somebody plis help me with Q1 (e)
I'm confused with the negative sign here
like should m= k+pAg
or m= -k-pAg

 

[SIstudy]

it's gradient = - (k+pAg)

the -ve sign should cancel at some point or the ans may be -ve

is it okay if I write
m= -k-pAg
?

 

[adarsha]

afc://09ba817d02c813536e1c2295a58926c36d7cad8b/DCIM/102APPLE/IMG_2883.JPG

the answer is 20KJ

 

[adarsha]

https://www.dropbox.com/s/tfxmd42q05vh7cr/IMG_2883.JPG?dl=0

 

[Masoom Gilani]

Pleaseee Help me solve part b and tell me how you did it. I've already finished my A-Level a few months back and don't remember it anymore. My friend asked me this question and she means alot to me. Please Help. Thank You.

 

[Masoom Gilani]

i've tried to explain with much details at
http://physics-ref.blogspot.com/2014/05/physics-9702-notes-worked-solutions-for.html

(at the bottom)

if there's any mistake, let me know. do you have the answers? (but I'm quite sure my answers are correct)

Also, I really need some help that I think you or your friend can provide. I really need this book from which you took this question (in softcopy) and all its associated resources. Could you send it to me. Or scan and upload it. It's the new physics coursebook 2014 for the new syllabus 2016.

Plz, see if you can send upload it. I would really appreciate

Thank You So Much!
I dont have the correct answers. I gave my Textbook to my friend and she has it but the textbook doesnt have the answers. We dont have the softcopy of the textbook, so sorry And scanning so many pages would be difficult, her exam is in less than a month's time. I'll try searching it online if i find i'll send it to you, for now i found this but its just the preview so doesnt contain all the pages.
http://books.google.com.my/books?id=SjsDBAAAQBAJ&printsec=frontcover#v=onepage&q&f=false

 

[JackAaron]

Hi guys,can you help me on Qn 1. b) ii)...thanks

 

[JackAaron]

November 2007 1. b) ii)*

 

[Bba321]

Does any one have Cambridge International AS Level and A Level Physics Coursebook by David Sang on mediafire?
I lost mine and cannot find it anywhere.Please helpp