Skema Jawapan Cofizik k3 2013

SKEMA JAWAPAN ( PAPER 3) SET 2

NUM. ANSWER MARKS1(a) i)mass // m 1

ii)rise in temperature //Ө 1

iii)density//(rate of) energy supplied 1

(b) V/cm3 m/g 1/m / g-1 T/ºC Ө/ ºC50 50 0.020 80 5560 60 0.017 75 5070 70 0.014 66 4180 80 0.013 60 3590 90 0.011 51 26

√ M1 column and label for v,m,1/m, T& Ө shown 1√ M2 units correct 1√ M3 all values for v correct 1√ M4 all values for m correct 1√ M5 all values for 1/m correct 1√ M6 all values for 1/m 3 d.p. 1

√ M7 all values for Ө correct. 1

Num. of √ Marks7 76 65 54 43 32 21 1

(c)√ A y axis labeled Ө and x axis labeled 1/m√ B unit for y axis and x axis are correct√ C even and constant scale for graph

√ √ D D 5 points are plotted correctly√ D 4 or 3 points are plotted correctly

√ E the best straight line is drawn√ F size of graph is more than half of graph paper

Num. of √ Marks17 5

6 4 15 4 14 3 13 3 12 21 1

- Ө is directly proportional to 1/mOr- Ө increases with 1/m

1(base on graph plotted by student)

2(a) i) x is inversely proportional to a 1

ii) If a = 2.0 m 11/a = ½ 0.5 m-1

1From the graph x = 1.5 m 1

iii) Triangle = 1.5/0.6 = 2.5 111

1(b) λ = ax /D = 2.5/D m 1

1Gradient = x/1/x = ax = 2.5/5 = 0.5 m 1

(c) This experiment is done in an open space to reduce the 1 effect of reflection.