## Pages

### EXAM

JAWAPAN KERTAS 2 (PEPERIKSAAN PERTENGAHAN TAHUN 2012 T4)

BAHAGIAN A

No
Marks

Question 1

1(a)(i)
(ii)
Mercury / merkuri / raksa
Expand / mengembang
1
1
(b)(i)
(ii)
X
Smaller scale is the smallest / skala terkecil paling kecil
1
1

Jumlah
4

Question 2

2(a)(i)

(ii)
Rate of change of displacement / kadar perubahan sesaran / sesaran
Masa
DE
1

1
(b)
Total displacement = ½(12 + 6)(10) - ½(2)(10)       - gantian
= 80 m                                    - jwpn dgn unit betul
1
1
(c)

1

Jumlah
5

Question 3

3(a)
3.0 kg ms-1
1
(b)(i)
(ii)
Opposite
Same / equal / sama
1
1
(c)(i)

(ii)
m1v1 + m2v2 = 0
(1.5)(2) + (0.01)( v2) = 0
v2 = 300 ms-1

0

1
1

1

Jumlah
6

Question 4

(a)
15 N
1
(b)(i)

(ii)

(iii)
Angle in Diagram 4.2 > Diagram 4.1

dgn gambarajah betul  (cth seperti di bawah)
skala yang sesuai

T1 = 8.8 N    +  0.1
T2 = 10.8 N  +  0.1

The bigger the size of angle, the greater the tension of the strings.
1

1  +  1

1  +  1

1

Jumlah
6

Question 5

(a)
Friction // weight // pulling
1
(b)
Force exerted on box in Diagram 6.1 less than 6.2
1
(c)
Time taken to move box in Diagram 6.1 is longer than than 6.2
1
(d)
Acceleration in Diagram 6.1 is smaller than 6.2
1
(e)(i)
(ii)
The greater the force the higher the acceleration
Newton’s Second Law
1
1
(f)(i)
(ii)
Acceleration decrease
Acceleration inversely proportional to mass.
1
1

Jumlah
8

BAHAGIAN B

No
Marks
6(a)(i)
Speed is the rate of distance travelled by an object
1
(a)(ii)
In Diagram 6.1, forces on car and tree are in the opposite direction
but magnitude are the same.
Magnitude of force in Diagram 6.2 is bigger than in Diagram 6.1.
Speed of car in Diagram 6.2 is higher than in Diagram 6.1.
The bigger the magnitude of force, the higher the speed.
1
1
1
1
1
(b)
When the ball is thrown up,
the kinetic energy decrease / gravitational potential energy increase
and it decelerate
Gravitational potential energy is maximum as the ball reaches the highest height before it goes down.
As the ball goes down, the kinetic energy increase / the accelerates

1
1

1
1
(c)

Diagram

1 (design)
1 (label)

(c)(i)
Material for container – plastic
because it light

1
(c)(ii)
Volume of water – one third (1/3)  of the bottle’s volume
because it left enough space for the compressed air
1
1
(c)(iii)
Launching angle stable - 45°
because it gives the best projectile.
1
1
(c)(iv)
Fin at the side of the rocket –
for rocket stability
1
1

Jumlah
20

BAHAGIAN C

No
Marks
7(a)(i)
Speed is the rate of distance travelled by an object
1
(a)(ii)
-  Fan produces a high speed movement of air backward.
-  This produces a large momentum backward.
-  By conservation of momentum, an equal magnitude
but opposite  direction
of momentum is produced and acted on the boat.
-     So the boat will move forward.

1
1
1
1
1
(b)(i)

(ii)
m (15) = (150 + 20)(6)
m = 68 kg

Total momentum of air (backward) equal to total momentum of the boat (forward)

1
1 + 1

1
(c)

 Suitable characteristics Reason Bottom shape – flat Move easily in the swam Size of motor - small Light Body material – aluminium Light / long lasting Propeller material – hard stainless stell Strong / long lasting

Most suitable is P,
Because it has flat bottom shape, small size of motor, body material from aluminium and propeller material from hard stainless steel

1+1
1+1
1+1
1+1

1

1

Jumlah
20

JAWAPAN UJIAN 2 (JULAI 2012) T5

BAHAGIAN A
 1 D 6 C 11 D 16 A 2 B 7 C 12 D 17 D 3 B 8 D 13 A 18 D 4 A 9 C 14 C 19 B 5 B 10 C 15 B 20 D

BAHAGIAN B

No
Mark

Q1

(a)
(c)

 Arah anak panah Magnetic field line -  bukan garis putus-putus

1
1

(b)(i)
North
1
(ii)
Right – hand grip rule
1
(d)
Increase the number of turns of the coil //
Increase the current //
Use soft iron as the core
1

JUMLAH
5

Q2

(a)
Lenz’s Law state that the direction of current induced will oppose the  change
which causes of it
1
(b)
P – North
Q - South
1
1
(c) 1
(d)
Increase the rate of motion of magnetic bar //
Increase the number of turn of coin in the solenoid //
Increase the strength of the bar magnet
1

(e)
Galvanometer pointer will deflected  in opposite direction
1

JUMLAH
7

Q3

(a)(i)
Soft iron
1
(ii)
Easily to magnetized and demagnetized
1
(iii)
V    =  125
240      2000

V  =  15V                                                        dengan unit yang betul
1

1
(b)(i)
Normal brightness means that  the voltage supplied to a bulb is the same as the voltage ratings on the bulb.
1
(ii)
12 + 12 + 12 = 36 V
1
(iii)
Power input  = Power output
V1I1    =   V2I2
(240) I1   = (36) x  (2)                                  gantian betul
I1  = 0.3 A                                         dengan unit yang betul

1
1

JUMLAH
8