SKEMA FIZIK KERTAS 2 PEPERIKSAAN DIAGNOSTIK PERTENGAHAN TAHUN 2007

SECTION A (52 M)QUESTION SUGGESTED ANSWER MARK

1(a)(i) Ratchet 1

(ii) To prevent the user from exerting undue pressure on the object. 1

(b) (i) Second reading 1

(ii) To reduce (random) error 1 TOTAL 4

2 (a) 1.5 cm / 20 = 0.075 cm = 0.75 mm 1

(b) This method can improve the sensitivity of a meter rule so that it can measure up to a sensitivity of 0.01 mm / reduce error.1

(c) Systematic error end error / zero errorRandom error parallax error11

(d) Use micrometer screw gauge 1TOTAL 5

3 (a) Diagram 3.1 derived Diagram 3.2 base 11

(b)

Diagram 3.1 derived quantity is the quantity which can be defined in terms of other physical quantity Diagram 3.2 base quantity is the quantity which cannot be defined in terms of other physical quantity

1

1

(c)90 x 10 3 = 25 ms-13.6 x 103

11

TOTAL 6

4 (a)(i) Distance, unit meterTime, unit second11

(a)(ii) Speed, ms-1 1

(a)(iii)Distance = speed x time = 75 kmh-1 x 2 h = 150 km

11

1

(b)

V = 7 cm x 5 cm x 12 cm = 420 cm3 = 420 x 10-6 = 4.2 x 10-4 m3

1

1TOTAL 7

5 (a)Diagram 5.1 the boy and skateboard move together in the same direction.Diagram 5.2 the frog and leaf move in the opposite direction

1

1 (b(i) same 1

b(ii)Momentum before = momentum after 40 x 20 = (40 + 2) v v = 19.05 ms-1

11

b(iii) The principle of conservation of momentum 1

c(i)Momentum = m x v = 30 x 20 = 600 kgms-1

11

c(ii) The boy has larger momentum than the girl 1

c(iii) The boy has larger mass // the higher the mass, the higher the momentum 1

TOTAL 9

6 (a)(i) Diagram 6.1 has less stretching force than Diagram 6.2 //Diagram 6.2 has more stretching force than Diagram 6.1 1

(a)(ii) Diagram 6.1 has less work done than Diagram 6.2 //Diagram 6.2 has more work done than Diagram 6.1 1

(a)(iii)Work done = Fx = (50) (0.2) = 5 J

11

(b)(i) Diagram 6.1 has less energy than Diagram 6.2 1 (b)(ii) Diagram 6.1 has less distance of projection than Diagram 6.2 1 (b)(iii) The higher the energy gained, the higher the distance of

projection1

(c) Use thicker elastic string //Increase the pulling force of arrow 1

TOTAL 8

7.(a) Acceleration ( a ) = -25/5 = -5 ms-211

2

-5

a

(b)i v decreases 1

(ii) 25 ms-1

Show the extrapolation graph11

c(i) A = (5)(25) = 62.5 m11

( ii) Displacement/distance of the car

1

d(i) Deceleration 1

(ii) 5 s 1

(iii)

1

1

TOTAL 12

3

t

Pattern graph

Graph axis

SECTION B(20 M)

8.a (i) A way of representing a numerical value in the form of A X 10n, where 1 A < 10 and n is an integer

1

(ii) - The length of the rope is approximately same as the length needed so that the length is not too long or too short.

- The density of the rope has to be small to make it light

- The hardness of the rope should be more than the weight of parachutist to ensure that the rope is not easily break.

- The diameter of the rope has to be moderate to make it comfortable to hold while controlling the parachute.

- The best choice is K because the length is approximately the same as needed, low density, snapping force is bigger than the load and moderate diameter

2

2

2

2

2

b.(i) Scalar quantity is a physical quantity with magnitude onlyVector quantity is a physical quantity with magnitude and direction.

11

(ii) Any example for Vector quantity Displacement, acceleration Scalar quantity Distance , speed

1

c.(i) 20 = 0 + (10)t2 t = 2 s

11

(ii)v/ms-1

t/s a/ms-2

t/s

2

2

TOTAL 20

4

SECTION C (28Marks)

Question Answer scheme Mark 9. a (i) State the manipulated variable correctly ;

Quantity of heat supplied / time for heating 1a (ii) State the responding variable correctly ;

Rise in temperature1

a (iii) State one fixed variable; Mass of Water

1

b = 25 C 1

c Tabulate t and correctly in the table that shows t as manipulated variable and as the responding variableGives base on the following aspect:

A Shows a table which have t, Give B State the correct unit of t, Give C All values of t are correct Give D Values of , are correct Give

Scoring:t / min / C

0 255 3610 4715 5820 6925 80

4

(d) Draw the graph of temperature, against time ,t.

A - The responding variable, at Y axis and manipulated variable, t at X axis: Give B - States the unit of the variable Give

C - Both axes with the even and uniform scale: Give

D - 6 points correctly plotted: Give Note: 4 5 points correctly plotted : Give

E - a smooth best fit straight line Give

5

F - minimum size of the graph is 5 x 4 Give squares of 2 x 2 cm: ( From the origin to the last point)

G - title of the graph Give

Number of Score8 77 6

5-6 5 4 4

3 32 21 1

7

e State the correct relationship based on the candidates graph ( positive gradient straight line graph) The increasing linearly with the t

1

TOTAL 16

Question Answer Scheme Mark10.a(i)

State the relationship between T2 and m correctlyT2 is directly proportional to m ( or T2 m) 1

a(ii) Calculate the Period, T

m = 55 g T2 = 3.6 S2 T = 1.89 s Show horizontal line parallel to the axis with the m

1

1

1 a(iii) Calculate the gradient of the graph and state the value within

the acceptable range

Show the triangle with an acceptable size ( 4 x 4 squares of 2 cm)Substitute correctly ( according to the candidates graph)

1

6

gradient = 3.25 - 0 s2 50 - 0 g

State the correct value of the gradient with unit

0.065 s2 g-1

2

1

(b) If T = 1.2s T2 = 1.44 s2

From the Graph if T2 = 1.44 s2 m = (22 1) g Show vertical line parallel to the axis with the T2

1

1

1

c) State precaution to produce an accurate result of the experiment

For every value of m, the experiment is repeated to obtain the average value of T

1

Total 12TOTAL MARKS FOR SECTION C (Q1 + Q2) 28 m

7