Unformatted text preview: since DU is positive, Q must be also). For stating the first law of thermodynamics, whether used correctly or not, OR for correctly explaining all three variables without reference to the first law of thermodynamics 2008 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 1 point 1 point AP PHYSICS B 2008 SCORING GUIDELINES
Question 5 (continued)
Distribution of points (c) 3 points For correctly relating states B and C at a constant temperature, using either the ideal gas law or Boyle's Law PV PBVB = C C or PBVB = PC VC TB TC For the correct substitution of the appropriate values P 5 atm VC = B VB = 0.001 m3 PC 1 atm For the correct answer including units VC = 0.005 m 3 1 point ( )( 1 point ) 1 point Alternate solution For correctly relating states A and B at a constant volume, using the ideal gas law, to determine the temperature TB Alternate points 1 point PAVA PV = B B TA TB TB = PB 5 atm T = ( 400 K ) = 2000 K PA A 1 atm
1 point ( ) For realizing that TC = TB and correctly relating states A and C at constant pressure, using the value of TB and the ideal gas law or Charles' Law to calculate VC . PV PAVA = C C TA TC VC = or TC T 2000 K V = BV = 0.001 m3 TA A TA A 400 K For the correct answer, including units VC = 0.005 m 3 ( V VA = C TA TC )( )
1 point Another method is to use the ideal gas law to calculate TB , set TC = TB , and once again use the ideal gas law to calculate VC . 2008 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. AP PHYSICS B 2008 SCORING GUIDELINES
10 points total Distribution of points (a) 3 points For a correct ray, correctly drawn (must reflect off mirror and must extend below principal axis) For a second correct ray, correctly drawn (must reflect off mirror and must extend below principal axis) For an inverted image located to the right of C and at the location where the rays converge 1 point 1 point 1 point (b) 2 points For correctly indicating that the image is real For a correct justification with no incorrect statements Examples of correct responses include: Image is inverted. Image is on the same side of the mirror as the object ( si > 0 ) . Light from the object passes through the image point. Rays converge at the imag...
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This note was uploaded on 02/09/2011 for the course PHYS 10 taught by Professor Davidnewton during the Spring '11 term at DeAnza College.
- Spring '11