Author Topic: Edexcel PHYSICS Doubts  (Read 135953 times)

Offline guMnam

  • !!~~**~~!!
  • SF Farseer
  • *******
  • Posts: 4242
  • Reputation: 12471
  • Gender: Male
  • !!~~guMnam~~!!
Re: Edexcel PHYSICS Doubts
« Reply #915 on: May 12, 2012, 10:06:47 pm »
jan 2010 unit 1 q6 can someone explain ?

I <3 Challenges
Never give up :)

Offline mustafa09

  • Newbie
  • *
  • Posts: 15
  • Reputation: 45
Re: Edexcel PHYSICS Doubts
« Reply #916 on: June 10, 2012, 09:17:08 pm »
can someone please explain how can i use Fleming left hand rule to find the charge in a hydrogen bubble chamber????? ??? ??? ???

Offline MKh

  • SF Geek
  • ****
  • Posts: 486
  • Reputation: 65535
Re: Edexcel PHYSICS Doubts
« Reply #917 on: June 10, 2012, 10:10:03 pm »
can someone please explain how can i use Fleming left hand rule to find the charge in a hydrogen bubble chamber????? ??? ??? ???

http://en.wikipedia.org/wiki/Fleming's_left-hand_rule_for_motors
Hope this helps.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #918 on: July 06, 2012, 11:17:53 pm »
you can only use the left hand rule to find the sign of a charge, and only if you know the direction it is moving in.

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #919 on: August 20, 2012, 05:41:59 am »
Hi! Can I get the answer for this question, ASAP, please?
An athlete throws a javelin. Just as it hits the ground the javelin has a horizontal velocity component of 22.0 m/s and a vertical velocity component of 11.0 m/s. What is the magnitude of the javelin's velocity as it hits the ground?

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #920 on: August 20, 2012, 09:54:15 am »
sqrt(22^2+11^2)=24.6m/s

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #921 on: August 22, 2012, 09:08:28 am »
Thankss a lot!! :) realised later that it was so easy...

I have a few more questions..
http://www.xtremepapers.com/papers/Edexcel/Advanced%20Level/Physics/2008%20Jan/6731_01_que_20080116.pdf
- Question no. 3) b)i)  and   5) c)ii)
hope you can give the answers for these two questions....:)
thanks once again!

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #922 on: August 23, 2012, 07:00:31 pm »
Thankss a lot!! :) realised later that it was so easy...

I have a few more questions..
http://www.xtremepapers.com/papers/Edexcel/Advanced%20Level/Physics/2008%20Jan/6731_01_que_20080116.pdf
- Question no. 3) b)i)  and   5) c)ii)
hope you can give the answers for these two questions....:)
thanks once again!
Max speed will be at bottom. In travelling from P to Q the work done against friction is Force times distance =60F where F is the average force. This is the difference between the initial and final energy
60F=mgh (at P) -1/2mv^2 at Q
60F=750*9.8*50-1/2*750*27^2 =94125 so F=94125/60=1568.75N

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #923 on: August 23, 2012, 07:03:28 pm »
And for 5cii constant deceleration so use suvat
s
u=0.95
v=0
a
t=9.3*10^-2
s=(u+v)/2*t=0.95/2*9.3*10^-2=0.044m
« Last Edit: August 23, 2012, 07:07:18 pm by astarmathsandphysics »

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #924 on: August 25, 2012, 04:05:43 pm »
Max speed will be at bottom. In travelling from P to Q the work done against friction is Force times distance =60F where F is the average force. This is the difference between the initial and final energy
60F=mgh (at P) -1/2mv^2 at Q
60F=750*9.8*50-1/2*750*27^2 =94125 so F=94125/60=1568.75N
why is the workdone against friction taken as 60F?
and, the answer isn't matching with the marking scheme. it says, answers in the range of 1100N-1300N
here's the link
http://www.xtremepapers.com/papers/Edexcel/Advanced%20Level/Physics/2008%20Jan/6731_01_rms_20080306.pdf
Q3) b)i)

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #925 on: August 25, 2012, 04:27:17 pm »
Thought it said distance is 60m but is 80
80F=750*9.8*50-1/2*750*27^2 =94125 so F=94125/80=1177N

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #926 on: August 25, 2012, 04:31:59 pm »
Thought it said distance is 60m but is 80
80F=750*9.8*50-1/2*750*27^2 =94125 so F=94125/80=1177N
ohh..okay..Thanks a lot :)
i have another question:
http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/sam-gce-physics.pdf
q 22) c)ii)

Offline Saladin

  • The Samurai
  • Honorary Member
  • SF V.I.P
  • *****
  • Posts: 6530
  • Reputation: 59719
  • Gender: Male
  • I believe in those who believe in me
    • Student Tech
Re: Edexcel PHYSICS Doubts
« Reply #927 on: August 25, 2012, 06:17:02 pm »
What is particularly difficult about the question? They just ask you to calculate tension. Also, its not always a good idea to do questions from SAMs because they often have errors in them.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #928 on: August 26, 2012, 11:15:17 am »
22cii

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #929 on: August 26, 2012, 05:48:07 pm »
What is particularly difficult about the question? They just ask you to calculate tension. Also, its not always a good idea to do questions from SAMs because they often have errors in them.
I had been thinking whether the 2 forces are going to b equal or not. So got confused. And I have seen this question not only from SAMs but from another site as well, with some other questions. Our physics teacher gave this question. Anyways, thanks for the info and help! :)