Author Topic: Edexcel PHYSICS Doubts  (Read 138079 times)

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #930 on: August 26, 2012, 05:48:48 pm »

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #931 on: August 26, 2012, 08:40:12 pm »
no probs

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #932 on: August 27, 2012, 05:46:54 pm »
Can anyone please give me the answer for these qustns.
a) A car of mass 1200kg is in a crash. The front bumper of the car deforms and the car is brought to rest from an initial speed of 10m/s in a distance of 0.12m. by considering the workdone on the car as it s brought to rest, calculate the average impact force that acts.
b) Modern cars crumple zones to reduce the size of the impact force. Suggest how the crumple zones do this.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #933 on: August 27, 2012, 09:10:50 pm »
xainer here you are

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #934 on: August 28, 2012, 03:31:00 pm »
xainer here you are
thanks! but why does longer distance decrease the value of F?

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #935 on: August 28, 2012, 03:32:50 pm »
thanks! but why does longer distance decrease the value of F?
is it because force is inversely proportional to the distance according to the equation??
what's the concept behind it?

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #936 on: August 28, 2012, 05:12:50 pm »
Force is inversely proportional to distance because force times distance equalsenergy which is constant
« Last Edit: August 30, 2012, 05:33:44 pm by astarmathsandphysics »

Offline xainer

  • Newbie
  • *
  • Posts: 23
  • Reputation: 36
Re: Edexcel PHYSICS Doubts
« Reply #937 on: August 30, 2012, 12:01:13 pm »
Oh! Thanks a lot :)

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #938 on: August 30, 2012, 05:34:23 pm »
Suggest you read my post above again. V bad English.

Offline jenifer911

  • Newbie
  • *
  • Posts: 3
  • Reputation: 13
Re: Edexcel PHYSICS Doubts
« Reply #939 on: April 02, 2013, 12:27:13 pm »
Hi everyone,

Could any one solve the following problem for me??? it can be found on the edexcel a2 physics book p.41 Questions 4.

4. In the electron beam of a CRO, electrons are accelerated through a potential difference of 3000V which is set up between electrodes 3cm apart.
a)Calculate the electric field strength, assuming it is a uniform field
b) How fast will the electrons be moving when htey emerge from this field?

Im having problems with (b), the answer 1.62 x 10^7 m s-1 while my calculations are double it i.e. 3.25X10^7ms-1

Thx in advance!!

Offline yo2646126

  • Newbie
  • *
  • Posts: 1
  • Reputation: 12
Re: Edexcel PHYSICS Doubts
« Reply #940 on: April 04, 2013, 10:30:46 pm »
...

Offline jenifer911

  • Newbie
  • *
  • Posts: 3
  • Reputation: 13
Re: Edexcel PHYSICS Doubts
« Reply #941 on: April 08, 2013, 07:23:36 am »
Oh my mistake, thanks:)

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #942 on: November 08, 2013, 05:56:09 pm »
Hi everyone,

Could any one solve the following problem for me??? it can be found on the edexcel a2 physics book p.41 Questions 4.

4. In the electron beam of a CRO, electrons are accelerated through a potential difference of 3000V which is set up between electrodes 3cm apart.
a)Calculate the electric field strength, assuming it is a uniform field
b) How fast will the electrons be moving when htey emerge from this field?

Im having problems with (b), the answer 1.62 x 10^7 m s-1 while my calculations are double it i.e. 3.25X10^7ms-1

Thx in advance!!
a)E=V/d=3000/0.03=100000 V/m
b)eV=\frac{1}{2}mv^2
so v= \sqrt{\frac{2eV}{m}} = \sqrt{\frac{2*1.6*10^{-19} *3000}{9.1*10^{-31}}} = 3.25*10^7 m/s

Offline studx3m

  • Newbie
  • *
  • Posts: 1
  • Reputation: 0
  • Gender: Female
Re: Edexcel PHYSICS Doubts
« Reply #943 on: April 19, 2014, 04:27:48 pm »
hey ppl!! m really really struggling with uncertainty precision and accuracy calculations!!!! please help meee (a2 unit 6 edexcel)
also can anyone tell me why the answer is C to may 2010 unit 3b edexcel physics??
m a private student in physics! so i have no idea how to prepare for unit 6!!! any practicals that i have to know??
practice makes perfect

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Edexcel PHYSICS Doubts
« Reply #944 on: April 24, 2014, 11:43:47 am »
I dont have the paper and it is not on the edexcel website.
Canyou post it?