Tuesday, October 21, 2014

9702 June 2010 Paper 22 Worked Solutions | A-Level Physics

  • 9702 June 2010 Paper 22 Worked Solutions | A-Level Physics


Paper 22


Question 1
Metal wire has cross-section of diameter approximately 0.8mm
(a)
Instrument used to measure diameter of wire:
Micrometer / screw gauge / digital calipers

(b)
How instrument in (a) is
(i)
Checked so as to avoid systematic error in measurements:
To look/check for zero error

(ii)
Used so as to reduce random errors:
By taking several readings around the circumference / along the wire



Question 2
(a)
Distance s moved by object in time t may be given by          s = ½ at2          where a is acceleration of object.
2 conditions for expression to apply to motion of object:
Choose any 2:
Initial speed is zero
Constant acceleration
Straight line motion

(b)
Student takes photograph of steel ball of radius 5.0cm as it falls from rest. Image of ball is blurred, as illustrated. Image is blurred because ball is moving while photograph is being taken.
Scale shows distance fallen from rest by ball. At time t = 0, top of ball is level with the zero mark on scale. Air resistance is negligible.
Calculate, to appropriate number of significant figures,
(i)
Time the ball falls before photograph is taken:
s = ½ at2
0.79 = ½ (9.8) t2
t = 0.40s

(ii)
Time interval during which photograph is taken:
Total distance travelled by the end of the time interval = 90cm
0.90 = ½ (9.8) t2
So, t = 0.43s
Time interval = 0.43 – 0.40 = 0.03s

(c)
Student in (b) takes second photograph starting at same position on scale. Ball has same radius but is less dense, so that air resistance is not negligible.
Changes that will occur in photograph:
Air resistance being not negligible means the ball’s speed / acceleration is less. So, the length of the image is shorter.
 


Question 3
{Detailed explanations for this question is available as Solution 437 at Physics 9702 Doubts | Help Page 83 - http://physics-ref.blogspot.com/2015/03/physics-9702-doubts-help-page-83.html}


 


Question 4
{Detailed explanations for this question is available as Solution 621 at Physics 9702 Doubts | Help Page 123 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-123.html}





Question 5
{Detailed explanations for this question is available as Solution 630 at Physics 9702 Doubts | Help Page 125 - http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-125.html}





Question 6
{Detailed explanations for this question is available as Solution 978 at Physics 9702 Doubts | Help Page 202 - http://physics-ref.blogspot.com/2015/09/physics-9702-doubts-help-page-202.html}



  
 
Question 7
{Detailed explanations for this question is available as Solution 644 at Physics 9702 Doubts | Help Page 128 - http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-128.html}



22 comments:

  1. how does alpha particles have kinetic energy initially?

    ReplyDelete
    Replies
    1. If it was moving (its velocity is not zero), then it has kinetic energy.

      The alpha particles can be released from particle accelerators (may be). You don't need to know about these things though at A-Level.

      Or from radioactive decay. When an element decays, the particles formed won't be stationary but they would move.

      Or they can be accelerated in electric and magnetic fields, causing them to have some velocities and thus, kinetic energy.

      ... The situations are many.

      So, it is not something strange. You just need to know that it is possible for them to have energies. I have stated examples for kinetic energy but there may be other forms of energies.

      Delete
  2. How does kinetic energy affects that mass-energy is conserved?

    ReplyDelete
    Replies
    1. This is the conservation of energy.
      Normally, in nuclear reactions, the energy is from the masses of the particles. But even if the mass is not enough to provide the required amount of energy, if the other particles are moving, they have kinetic energy and this energy is transferred.

      Delete
  3. Can you provide the graph for question 6(c) thank you :D

    ReplyDelete
    Replies
    1. the graph is available above. As I noted, it can be drawn better. It's difficult to draw on the computer. You should draw it better

      Your graph should have the same shape. It's not a straight line, but a curve

      Delete
  4. How do we calculate to find the ammeter reading(current) ? If let say 100cm =5 ohm then 1 cm =0.05 ohm, hence for midpoint , 50cm, =2.5 ohm And hence I= V/R = 1.5/ 2.5
    So the answer should be 0.6 A but why 1.2? And is the graph a straight line?
    Thank you !

    ReplyDelete
    Replies
    1. I've added the details above. Read it and see if you understand

      Delete
  5. Could you provide the graph for Question 3(c) please? Thank you.

    ReplyDelete
  6. Can you please solve question 5b of June 2010 paper 23 :s

    ReplyDelete
    Replies
    1. Explained as solution 566 at
      http://physics-ref.blogspot.com/2015/04/physics-9702-doubts-help-page-111.html

      Delete
  7. can you please draw the following: (its urgent)
    -Q2(b) and Q3d(ii) of June 2011 paper 23
    -Q1c(ii) and Q2(c) of June 2012 paper 23

    ReplyDelete
    Replies
    1. For June 2012 Paper 23 Q1, see solution 703 at
      http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-142.html

      For June 2012 Paper 23 Q2, see solution 670 at
      http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-134.html

      Delete
  8. For Q6d 2010 MJ v22, why Is the resistance at AB not equal to BC?

    ReplyDelete
  9. how does s=0.79 in 2b(i)?

    ReplyDelete
  10. ohhh its ok i didnt read it correctly... for 2b(i)

    ReplyDelete

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