PHYSICAL SCIENCES: PHYSICS (PAPER 1)
GRADE 12
NOVEMBER 2019
MEMORANDUM
NATIONAL SENIOR CERTIFICATE
QUESTION 1
1.1 C ✓✓ (2)
1.2 A ✓✓ (2)
1.3 A✓✓ (2)
1.4 D ✓✓ (2)
1.5 B ✓✓ (2)
1.6 D ✓✓ (2)
1.7 A ✓✓ (2)
1.8 B ✓✓ (2)
1.9 D ✓✓(2)
1.10 C ✓✓ (2)
[20]
QUESTION 2
NOTE: -1 mark for each key word/phrase omitted in the correct context (2)
2.1 When a resultant/net force acts on an object, the object will accelerate in the direction of the force with an acceleration that is directly proportional to the force and inversely proportional to the mass of the object. ✓✓
OR
The resultant/net force acting on an object is equal to the rate of change of momentum of the object (in the direction of the resultant/net force.) ✓✓ (2)
2.2
Accept the following symbols | |
N | FN/Normal/Normal force |
f | Ff / fk / fr / frictional force/kinetic frictional force |
W | Fg,/mg/weight/FEarth on block/19,6 N/gravitational force |
T | Tension/FT / FA / F / Fs |
Notes
2.3
For the 2 kg (P) block: Fnet = ma T + (- wll) + (- fk) = ma T – (wll + fk) = ma T – (2)(9,8)sin30°✓ – 2,5✓= 2a ✓ T – 9,8 – 2,5 = 2a T – 12,3 = 2a ……….(1) For the 3 kg (Q) block: Fx + (-T) + (- wll) = ma Fx – (T + wll) = ma [40 cos 25°✓ – T – (3)(9,8)sin30°✓] ✓ = 3a 36,25 – T – 14,7 = 3a 21,55 – T = 3a ………….(2) 9,25 = 5 a a = 1,85 m∙s-2✓ | Marking criteria
|
Systems Approach (Massless String Approximation (Max 5/8 marks) Fnet = ma Fx + (- wll) + (- fk) = ma Fx – (wll + fk) = ma 40cos25° ✓ – (5)(9,8)sin30°✓ – 2,5✓= 5a a = 1,85 m∙s-2 ✓ |
(8)
2.4 Greater than
Fnet increases.
ACCEPT
There is no friction.
OR
The surface is smooth (2)
[16]
QUESTION 3
3.1 (Motion during which) the only force acting is the force of gravity. ✓✓ (2 or 0) (2)
3.2 Marking criteria:
OPTION 1
UPWARDS AS POSITIVE:
vf2 = vi2 + 2aΔy ✓
0 = (10)2 + (2)(- 9,8)Δy ✓
Δy = 5,10 m (5,102 m)
Height = 40 + 5,10 ✓
= 45,10 m ✓
DOWNWARDS AS POSITIVE:
vf2 = vi2 + 2aΔy✓
0 = (-10)2 + (2)( 9,8)Δy ✓
Δy = - 5,10 m (5,102)
Height = 40 + 5,10 ✓
= 45,10 m ✓
OPTION 2
UPWARDS AS POSITIVE:
vf = vi + aΔt
0 = (10) + (- 9,8)Δt
Δt = 1,02 s
Δy = viΔt + ½ aΔt2✓
= (10)(1,02) + ½ (-9,8)(1,02)2✓
= 5,10 m
OR
Δy=(v1 + vf)Δt
2
=(10 + 0)(1,02)
2
= 5.10m
Height = 40 + 5,10 ✓
= 45,10 m ✓
DOWNWARDS AS POSITIVE:
vf = vi + aΔt
0 = (-10) + ( 9,8)Δt
Δt = 1,02 s
Δy = viΔt + ½ aΔt2 ✓
= (-10)(1,02) + ½ (9,8)(1,02)2 ✓
= 5,10 m
Height = 40 + 5,10 ✓
= 45,10 m ✓
Accept swopping of vi and vf
OPTION 3
UPWARDS AS POSITIVE:
Δy = viΔt + ½ aΔt2
0 = (10) Δt + ½(-9,8)Δt2
Δt = 2,04 s
Δy = viΔt + ½ aΔt2✓
= (10)(1,02) +½ (-9,8)(1,02)2✓
= 5,10 m
Height = 40 + ✓5,10
= 45,10 m ✓
DOWNWARDS AS POSITIVE:
Δy = viΔt + ½ aΔt2
0 = (-10) Δt + ½(9,8)Δt2
Δt = 2,04 s
Δy = viΔt + ½ aΔt2✓
= (-10)(1,02) + ½ (9,8)(1,02)2✓
= - 5,10 m
Height = 40 + 5,10 ✓
= 45,10 m ✓
OPTION 4
UPWARDS AS POSITIVE:
Δy = viΔt + ½ aΔt2
0 = (10)Δt + ½(-9,8)Δt2
Δt = 2,04s
Δy=(v1 + vf)Δt
2
=(10 + 0)(1,02)
2
= 5.10m
Height = 40 + 5,10 ✓
= 45,10 m ✓
DOWNWARDS AS POSITIVE:
Δy = viΔt + ½ aΔt2
0 = (-10) Δt + ½(9,8)Δt2
Δt = 2,04 s
Δy=(v1 + vf)Δt
2
=(10 + 0)(1,02)
2
= 5.10m
Height = 40 + 5,10 ✓
= 45,10 m ✓
Accept swopping of vi and vf
OPTION 5
E(mech)roof = E(mech)top
(Ep + Ek)roof = (Ep + Ek)top
(mgh + ½ mv2)roof/dak = (mgh + ½ mv2)top
[m(9,8)(0) + ½m (10)2 = m(9,8) (h)+ 0)] ✓
h = 5,10 m
Height = 40 + 5,10 ✓
= 45,10 m✓
OPTION 6
Wnet = ΔEk ✓
wΔxcosθ = ½ mvf2 – ½ mvi2
(m)(9,8)Δxcos180º= 0 – ½ m(10)2✓
Δx = 5,10 m
Height = 40 + 5,10 ✓
= 45,10 m ✓
OPTION 7
Wnc = ΔEp + ΔEk✓
0 = m(9,8)(hf – 0) + ½ m( 0 – 102) ✓
hf = 5,10 m
Height = 40 + 5,10✓
= 45,10 m✓
OPTION 8
Marking criteria:
E(mech)roof = E(mech)top
(Ep + Ek)roof = (Ep + Ek)top
(mgh + ½ mv2)roof/dak = (mgh + ½ mv2)top
[m(9,8)(0) + ½m (10)2 = m(9,8) (h)+ 0)] ✓
h = 45,10 m (4)
3.3 9,8 m·s-2 ✓downwards✓ (2)
3.4 Marking criteria
OPTION 1
UPWARDS AS POSITIVE:
Displacement from roof to meeting point = -40 + 29,74 = - 10,26 m
Stone A
ΔyA = viΔt + ½aΔt2 ✓
-10,26 ✓= 10Δt + ½(-9,8)Δt2 ✓
Δt = 2,79 s
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
Stone B
ΔyB = viΔt + ½aΔt2
-10,26 = 0 + ½(-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45✓= 1,34 (s) ✓
OR
[-10,26 = 0(2,79 – x) + ½ (-9,8)(2,79 – x)2✓]✓
x = 1,34 (s)✓
DOWNWARDS AS POSITIVE:
Displacement from roof to meeting point= 40 - 29,74 = 10,26 m
Stone A
ΔyA = viΔt + ½aΔt2 ✓
10,26 = -10Δt + ½(9,8)Δt2 ✓
Δt = 2,79 s
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s)✓
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓ = 1,34 (s) ✓
OR
[-10,26 = 0(2,79 – x) + ½ (-9,8)(2,79 – x)2✓]✓
x = 1,34 (s) ✓
OPTION 2
UPWARDS AS POSITIVE:
Displacement from roof to meeting point = - 40 + 29,74 = - 10,26 m
Displacement of stone A from max height to meeting point = -15,36 m
Stone A
vf = vi + aΔt
0 = 10 +(-9,8)Δt
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2 ✓
-15,36 = 0 + ½(-9,8)Δt2 ✓
Δt = 1,77 s
Δttot = 1,77 + 1,02 = 2,79s
Stone B
ΔyB = viΔt + ½aΔt2
-10,26 ✓= 0 + ½(-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓ = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
DOWNWARDS AS POSITIVE:
Displacement from roof to meeting point = 40 - 29,74 = 10,26 m ✓
Displacement of ball A from max height to meeting point = 15,36 m
Stone A
vf = vi + aΔt
0 = -10 + (9,8)Δt
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2 ✓
15,36 = 0 + ½(9,8)Δt2 ✓
Δt = 1,77 s
Δttot = 1,77 + 1,02 = 2,79s
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓ = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
OPTION 3
UPWARDS AS POSITIVE:
Displacement of stones A and B from roof to meeting point = - 40 + 29,74 = - 10,26 m
Stone A
vf = vi + aΔt
0 = 10 + (-9,8)Δt
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2✓
- 10,26 = -10 + ½(-9,8) Δt2 ✓
Δt = 0,75 s
Δttot = 1,02 + 1,02 + 0,75 = 2,79 s
Stone B
ΔyB = viΔt + ½aΔt2
-10,26 = 0 + ½(-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s)✓
DOWNWARDS AS POSITIVE:
Displacement of stones A and B from roof to meeting point = 40 - 29,74 = 10,26 m
Stone A
vf = vi + aΔt
0 = -10 + (9,8)Δt
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2 ✓
10,26 ✓= 10 + ½ (9,8)Δt2 ✓
Δt = 0,75s
Δttot = 1,02 + 1,02 + 0,75 = 2,79 s
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓= 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45✓
= 1,34 (s)✓
OPTION 4
UPWARDS AS POSITIVE:
Displacement from roof to meeting point = - 40 + 29,74 = - 10,26 m
Stone A
ΔyA = viΔt + ½aΔt2
- 5,10 = 0 + ½(-9,8)Δt2
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2 ✓
- 10,26 = -10 + ½(-9,8)Δt2 ✓
Δt = 0,75s
Δttot = 1,02 + 1,02 + 0,75 = 2,79 s
Stone B
ΔyB = viΔt + ½aΔt2
-10,26 = 0 + ½(-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓= 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s)✓
DOWNWARDS AS POSITIVE:
Displacement from roof to meeting point = 40 - 29,74 = 10,26 m
Stone A
ΔyA = viΔt + ½aΔt2
5,10 = 0 + ½(9,8)Δt2
Δt = 1,02 s
ΔyA = viΔt + ½aΔt2 ✓
10,26 = 10 + ½(9,8)Δt2 ✓
Δt = 0,75s
Δttot = 1,02 + 1,02 + 0,75 = 2,79 s
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 = 1,34 (s)✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
OPTION 5
UPWARDS AS POSITIVE:
Displacement from roof to meeting point = - 40 + 29,74 = - 10,26 m
Displacement of stone A from max height to meeting point = -15,36 m
Stone A
vf2 = vi2 + 2aΔy
vf2 = (0)2 + (2)(- 9,8)(-15,36)
vf = - 17,35 m·s-1
vf = vi + aΔt
-17,35 = 0 + (-9,8)Δt ✓
Δt = 1,77 s
Δttot = 1,02 + 1,77 = 2,79 (s)
Stone B
ΔyB = viΔt + ½aΔt2
-10,26 = 0 + ½(-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s)✓
DOWNWARDS AS POSITIVE:
Displacement from roof to meeting point = 40 - 29,74 = 10,26 m
Displacement of stone A from max height to meeting point = 15,36 m
Stone A
vf2 = vi2 + 2aΔy
vf2 = (0)2 + (2)(9,8)(15,36)
vf = - 17,35 m·s-1
vf = vi + aΔt
17,35 = 0 + (9,8)Δt ✓
Δt = 1,77 s
Δttot = 1,02 + 1,77 = 2,79 (s)
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓ = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(9,8)(10,26)
vf = 14,18 m·s-1
vf = vi + aΔt
14,18 = 0 + (9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
OPTION 6
UPWARDS AS POSITIVE:
Displacement from roof to meeting point/Verplasing vanaf dak tot by ontmoetingspunt = - 40 + 29,74 = - 10,26 m
Stone/Klip A
vf2 = vi2 + 2aΔy
vf2 = (-10)2 + (2)(- 9,8)(-10,26)
vf = - 17,35 m·s-1
vf = vi + aΔt
-17,35 = -10 + (-9,8)Δt ✓
Δt = 0,75 s
Ball A: Δt = 1,02 + 1,02 + 0,75 = 2,79 (s)
Stone B
ΔyB = viΔt + ½ aΔt2
-10,26 ✓= 0 + ½ (-9,8)Δt2 ✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 = 1,34 (s)✓
vf2 = vi2 + 2aΔy
= 02 + 2(-9,8)(-10,26)
vf = -14,18 m·s-1
vf = vi + aΔt
-14,18 = 0 + (-9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
DOWNWARDS AS POSITIVE:
Displacement from roof to meeting point = 40 - 29,74 = 10,26 m
Stone/Klip A
vf2 = vi2 + 2aΔy
vf2 = [(10)2 + (2)(9,8)(10,26)
vf = 17,35 m·s-1
vf = vi + aΔt
17,35 = 10 + (9,8)Δt ✓
Δt = 0,75 s
Ball A: Δt = 1,02 + 1,02 + 0,75 = 2,79 (s) (6)
Stone B
ΔyB = viΔt + ½aΔt2
10,26 = 0 + ½(9,8)Δt2✓
Δt = 1,45 s (1,447 s)
x = 2,79 – 1,45 ✓ = 1,34 (s) ✓
vf2 = vi2 + 2aΔy
= 02 + 2(9,8)(10,26)
vf = 14,18 m·s-1
vf = vi + aΔt
14,18 = 0 + (9,8)Δt✓
Δt = 1,45 s
x = 2,79 – 1,45 ✓
= 1,34 (s) ✓
3.5.2 a ✓ (1)
3.5.3 f ✓ (1)
3.5.4 c ✓ (1)
[18]
3.5.1 d ✓ Accept / Aanvaar ( 0 – e; 0 – d; d – e) (1)
QUESTION 4
4.1 NOTE: -1 mark for each key word/phrase omitted in the correct context.
Isolated system is a system on which the resultant/net external force is zero.✓✓
OR
Isolated system is one that has no net / external force acting on it.(2)
4.2.1 p = mv ✓
24 = m (480) ✓
m = 0,05 kg ✓ (3)
4.2.2 Marking criteria
POSITIVE MARKING FROM QUESTION 4.2.1
OPTION 1
FnetΔt = Δp
FnetΔt = (pbullet)f - (pbullet)i
FnetΔt = (mvbullet)f - (mvbullet)i
Fnet(0,01) ✓ = (0,05)(80) – 24 ✓ or/of (0,05)(80) – (0,05)(480)
Fnet = -2 000 N
Fnet= 2 000 N ✓ west ✓
OPTION 2
vf = vi + aΔt
80 = 480 + a(0,01) ✓
a = - 40 000 m∙s-2
Fnet= ma ✓
= (0,05)(-40 000) ✓
= - 2 000 N
Fnet= 2 000 N ✓ west ✓
✓Any one
Note: p and v must have the same sign
OPTION 3
Δx =(v1 + vf) Δt
2
=480 + 80(0.01)
2
= 2,80 m
vf2 = vi2 + 2aΔx
(80)2 = (480)2 + 2a(2,80) ✓
a = - 40 000 m∙s-2
= ma ✓
= (0,05)(-40 000) ✓
= - 2 000 N
Fnet = 2 000 N ✓ west ✓
Wnet = ΔK ✓
Fnet Δxcosθ = ½mvf2 - ½mvi2
Fnet (2,80)cos0° ✓= ½(0,05)(802 - 4802) ✓
Fnet = -2 000 N
Fnet = 2 000 N ✓ west ✓
OR
Fnet (2,80)cos180° ✓ = ½(0,05)(802 - 4802) ✓
Fnet = 2 000 N ✓ west ✓ (5)
[10]
QUESTION 5
5.1 Note: -1 mark for each key word/phrase omitted in the correct context.
IF: The word "work" is omitted - 0 marks.
A conservative force is a force for which the work done (in moving an object between two points) is independent of the path taken. ✓✓
OR
A conservative force is a force for which the work done in moving an object in a closed path is zero.(2)
5.2 Gravitational (force) ✓
ACCEPT: Gravitation /Gravity/Weight (1)
5.3 No ✓
There is friction/non-conservative force (doing work)/It is not isolated system.✓
OR
The net work done by the non-conservative forces is not zero (2)
5.4 OPTION 1
EP = mgh ✓
= (1,8)(9,8) (1,5) ✓
= 26,46 J ✓
OPTION 2
Ww = -ΔEp ✓
(1,8)(9,8)(h – 0)cos180o = -(EpA – Ep(ground))
(1,8)(9,8)(1,5)(-1) = -EpA ✓
Ep = 26,46 J✓
OR
W = FΔxcosθ
= mgΔhcosθ
= (1,8)(9,8) (1,5)cos0o ✓
= 26,46 J✓ (3)
5.5 POSITIVE MARKING FROM QUESTION 5.4
OPTION 1
Wnc = ΔK + ΔU
Wf = ½m(vf2 – vi2) + mg(hf – hi)
= ½(1,8)(42 – 0,952) ✓+ (0 – 26,46) ✓
= -12,87 J ✓
OPTION 2
Wnet = ΔK
Wf + Wg = ½mvf2 - ½mvi2
Wf + mgh = ½m(vf2- vi2)
Wf + mgh = ½mvf2 - ½mvi2
Wf + 26,46✓= ½(1,8)[(4)2 - (0,95)2] ✓
Wf = -12,87 J (- 12,872 J)✓
OPTION 3
E(mech)A = E(mech)B - Wf
(Ep + Ek)A = (Ep + Ek) B - Wf
(mgh + ½ mv2) A = (mgh + ½ mv2) B - Wf
26,46 + ½(1,8)(0,952) ✓ = 0 + ½(1,8)(42) - Wf ✓
Wf = -12,87 J ✓ (4)
5.6 Wnet = 0 (J ) / zero✓(1)
[13]
QUESTION 6
6.1 Doppler effect ✓(1)
6.2 (Q): (records sounds with) longer period/ longer time per wave / lower frequency.
OR
P: (records sounds with) shorter period/ shorter time per wave / higher frequency. ✓
ACCEPT
(Q): longer wavelength. /P: shorter wavelength. (1)
6.3 OPTION 1
f = 1 ✓= 1 ✓ = 5,88 x 102 = 588,24 Hz ✓
T 17 x 10-6
OPTION 2
speed =distance
time
340 = distance
25.5 x 10-6
Distance = 0,867 m
Distance = 1 ½ λ
∴λ = 0,578 m
v = fλ ✓
340 = f(0,578) ✓
f = 588,24 Hz ✓
OPTION 3
v = λ
T
340 = λ
17 × 10-4
∴ λ = 0,578 m
v = fλ ✓
340 = f(0,578) ✓
f = 588,24 Hz ✓ (3)
6.4 POSITIVE MARKING FROM QUESTIONS 6.2 AND 6.3.
Do not penalise if 10-4 is again omitted.
OPTION 1
f = 1 = 5,56 x 102 = 555,56 Hz
18 x 10-4
fL = v ± vLfs OR fL = v fs
v ± vs v + vs
555,56 = 340 588.24
340 + v
v = 20 m∙s-1 ✓
Range 19,57 – 20,09 m·s-1
OPTION 2
f = 1
18 x 10-4
fL = v ± vLfs OR fL = v fs
v ± vs v + vs
1 = 340 1
18 x 10-4 340 + v 17 x 10-4
v = 20 m∙s-1 ✓
Range 19,57 – 20,09 m·s-1 (6)
[11]
QUESTION 7
7.1.1 Positive ✓ (1)
7.1.2 Marking criteria:
OPTION 1
F=kQ1Q2
r2
3.05 = (9 x 109)(6 x 10-6)Q
0.22
Q = 2,26 x 10-6 C ✓
(2,259 x 10-6 C)
OPTION 2
E = kQ
r2
= (9 x 109)(6 x 10-6)
0.22
= 1,35 x 106 N·C-1
F = Eq✓
3,05 = (1,35 x 106)q✓
q = 2,26 x 10-6 N✓ (3)
7.1.3
Accepted labels | |
w | Fg / Fw / weight / mg / gravitational force |
T | FT / tension / spanning |
FE/F | Electrostatic force/ Coulomb force/ FE Field/Fx on Y/ 3,05 N |
Notes
7.1.4 Fnet = 0
FE = Tsin10°
FE = Tcos80°
[3,05 = Tsin10°✓]✓ [IF Tcos10º = 3,05 (1/3)]
OR
[3,05 = Tcos80°✓]✓ [IF Tsin80º = 3,05 (1/3)]
T = 17,56 N (17,564 N) (3)
7.2.1 Marking criteria
The electric field at a point is the (electrostatic) force experienced per unit positive charge placed at that point. ✓✓
[IF the word “unit” or phrase “positive charge” is omitted in this definition: -1 for each
OR
The electric field at a point is the (electrostatic) force experienced by a UNIT positive charge placed at that point. ✓✓
[If “UNIT” is omitted in this definition, then 0 marks. (2)
7.2.2 OPTION 1
Electric field at M due to A (+2 x10-5 C):
EA = kQ
r2
= 9 x 109(2 x 10-6)
(0.2)2
= 4,5 x106 N∙C-1
Electric field at M due to B (-4 x10-5 C):
EB = kQ or qB =2qA
r2
= 9 x 109(4 x 10-6) EB=2EA
(0.2)2
= 9 x106 N∙C-1 = 9 x 106 N∙C-1
Enet at M = EA + EB
= (4,5 x 106 + 9 x 106) ✓
= 1,35 x 107 N∙C-1 ✓ to the right/towards B/away from A
OPTION 2
Net electrostatic force at M
Fnet = kQ1Q2 + kQ1Q2
r2 r2
= (9 x 109)(2 x 10-5)q + (9 x 109)(4 x 10-5)q (any one/ enige een)
(0.2)2 (0.2)2
= 4,5 x 106q +✓ 9 x 106q
= 1,35 x 107q N
Fnet = Enetq ✓
1,35 x 107q ✓= Enetq
Enet = 1,35 x 107 N.C-1 ✓to the right ✓/towards B (6)
[18]
QUESTION 8
8.1 (Maximum) energy provided (work done) ✓ by a battery per coulomb / unit charge passing through it. ✓
ACCEPT:
The reading on a voltmeter connected across a battery when there is no current/ in an open circuit.✓✓ (2)
8.2 13 V ✓ (1)
8.3.1 R = V
I
5.6 =10.5
I
I = 1,88 A ✓ (1,875 A)
Marking criteria:
8.3.2 POSITIVE MARKING FROM QUESTION 8.3.1.
OPTION 1
P = VI ✓
= (10,5)(1,88) ✓
= 19,74 W ✓ (19,688 W)
OPTION 2
P = I2R ✓
= (1,88)2(5,6) ✓
= 19,79 W ✓ (19,688 W)
OPTION 3
P = V2
R
=10.52
5.6
= 19,69 W ✓ (19,688 W) (3)
8.3.3 POSITIVE MARKING FROM QUESTIONS 8.2 AND 8.3.1.
OPTION 1
Ɛ = I(R + r) ✓
13 = 1,88 (5,6 + r) ✓
r = 1,31 Ω (1,31 – 1,33 Ω)
OPTION 2
r = Vinternal✓
I
= 2.5
1.88
= 1,33 Ω ✓ ( 1,31 – 1,33 Ω)
OPTION 3
Ɛ = Vext + Vint
13 = 10,5 + Vint
Vint = 2,5 V
Vint = Ir ✓
2,5 = (1,88)r✓
r = 1,31 Ω ✓ (1,31 – 1,33 Ω) (3)
8.4.1 Decreases ✓
Vinternal resistance ✓
Vinterne weerstand (2)
8.4.2 Marking criteria
POSITIVE MARKING FROM QUESTIONS 8.2 AND 8.3.3
OPTION 1
Ɛ = I(R + r) ✓
13 = 4 (Rext + 1,31) ✓
Rext = 1,94 Ω (1,92 Ω)
1 = 1 + 1
RP R1 R2
1 = 1 + 1
1.94 5.6 R2
R2 = 2.97Ω (2,92 Ω)
X= ½(2.97)
49,1 = Ω ✓ (1,46 – 1,49 Ω)
OPTION 2
Ɛ = I(R + r) ✓
13 = 4 (Rext + 1,31) ✓
Rext = 1,94 Ω (1,92 Ω)
RP = R1 R2
R1 + R2
1.94 = 5.6 R2
5.6 + R2
R2 = 2.97Ω (2,92 Ω)
X= ½(2.97)
49,1 = Ω ✓ (1,46 – 1,49 Ω)
OPTION 3
Ɛ = I(R + r) ✓
13 = 4 (Rext + 1,31) ✓
Rext = 1,94 Ω (1,92 Ω)
1 = 1 + 1
RP R1 R2
1 = 1 + 1
1.94 5.6 2X
X 49,1 = Ω ✓ (1,46 – 1,49 Ω)
OPTION 4
Ɛ = I(R + r) ✓
13 = 4 (Rext + 1,31) ✓
Rext = 1,94 Ω (1,92 Ω)
RP = R1 R2
R1 + R2
1.94 = 5.6(2X)
5.6 + 2X
X 49,1 = Ω ✓
OPTION 5
Ɛ = I(R + r) ✓
Vext = 13 – (4)(1,31) ✓
= 7,76 V
Vp = IR5,6
7,76 = I(5,6)
I5,6Ω = 1,37 A
IT = I2X + I5,6
4 = I2x + 1,37
I2X = 2,63 A
V = IR2X
[7,76 = (2,63)2X✓]✓
X = 1,46 Ω
OPTION 6
Ɛ = I(R + r)
Vext = 13 – (4)(1,31) ✓
Vext = 7,76 V
I5,6Ω = 7.76 = 1,39 A
5.6
I2x = 4 – 1,39 = 2,61 A
V2x = I2XR2X
[7,76 = (2,61)2X✓]✓
2X = 2,97 Ω
X = 1,49 Ω✓
VX = IXRX
3,88=(2,61)RX✓
RX = 1,49 Ω✓
OPTION 7
Ɛ = I(R + r)✓
Vext = 13 – (4)(1,31)✓
= 7,76 V
Vext = IRext
7,76 = (4)( 1 + 1 )-1
2X 5.6
X = 1,48 Ω ✓ (5)
[19]
QUESTION 9
9.1
9.1.1 DC ✓ (1)
9.1.2 NOTE: -1 mark for each key word/phrase omitted in correct context.
Emf is induced as a result of change of magnetic flux (linked) with the coil. ✓✓(2)
9.1.3 POSITIVE MARKING FROM QUESTION 9.1.1
9.2.1 The AC potential difference/voltage which dissipates the same amount of energy ✓ as DC potential difference. ✓
OR
(The rms value of AC is) the DC potential difference/voltage which dissipates the same amount of energy ✓ as AC potential difference/voltage. ✓(2)
9.2.2
(5)
[12]
QUESTION 10
10.1 Note: -1 mark for each key word/phrase omitted in correct context.
The process whereby electrons are ejected from a metal / surface when light (of suitable frequency) is incident on that surface. ✓✓ (2)
10.2 7,48 x 10-19 (J) ✓
E = Wo + Ek(max) (= Wo + ½mv2max) ✓
When Ek(max) = 0 / v = 0 / v2 = 0 / E = Wo / Wo is the y-intercept ✓ (3)
10.3 Mass (of photo-electron) ✓
ACCEPT :½m (1)
10.4 OPTION 1
Gradient = ½m
11.98 x 10-19 - 7.48 x 10-19 = ½(9,11 x 10-31) ✓
X - 0
X = 0,9879 ✓ (0,99 or 0,988)
ACCEPT
X = 0,9879 x 1012 (m2∙s-2)
POSITIVE MARKING FROM 10.2
OPTION 2
E = Wo + Ek(max)
E = Wo + ½mv2(max)
11,98 x 10-19 ✓ = 7,48 x 10-19 ✓+ ½(9,11 x 10-31) v2✓ [or ½(9,11 x 10-31)X]
4,5 x 10-19 = 4,56 x 10-31v2
v2 = 0,9868 x 1012
X/v2 = 0,9868 ✓ (0,99)
Range (0,9868 – 0,9879 / 9,87 x 1011 – 9,88 x 1011)
ACCEPT:
X = 0,9868 x 1012 (m2∙s-2) / 9,868 x 1011 (m2∙s-2) (5)
10.5.1 Remains the same ✓ (1)
10.5.2 Increases ✓ (1)
[13]
TOTAL: 150