13 June 2010
(a) (i) Based on the results in Table 1.1, state two observations for the experiment.
1. When the length of the straw is 20cm , the weight that bends the straw is 1N
2. When the length of the straw is 5 cm, the weight that bends the straw is 4N
[ 3 marks]
(ii) State the inference which corresponds to the observation in 1(a)(i).
1. When the length is short , the strength of the straw is strong /high
2. When the length is long (P1), the strength of the straw is weak / low.
[ 3 marks]
C (i) Complete Table 1.2 based on this experiment (Dependent)
| Variable | Method to handle the variable (Dependent) |
| Manipulated variable The length of the straw. | By using different length of straws, that is, 20cm, 15cm, 10cm and 5cm respectively. |
| Responding variable The weight that bends the straw. | By recording down the weight that bends the straws using the metal weights/ 0.5N |
| Controlled variable The diameter of the straw | By fixing the diameter of the straw at 1cm |
Table 1.2
[3 marks]
(ii) Complete the table 1.3 below by classifying the materials and apparatus used in this experiment
| Apparatus | Materials |
| Retort stand Hook Wooden blocks 50N weights | Straw Paper/ cotton |
Table 1.3 [3 marks]
e. State a hypothesis for the experiment.
The shorter the length, the higher the strength of the straw that bends the straw.
[3 marks]
f. Based on Table 1.1, record the results of this experiment obtained in a table. Your table should include the following aspects:
- The length of the straw
- Surface area of the straw (equals the length multiply by the 3cm2)
- The weight that bends the straw
- The strength of the straw, using the formula: Straw’s strength = Force (Weight) divided by the straw surface area
| Length (cm) | Surface area (cm2) | Weight / Force (N) | Strength = F/SA (N/cm2) |
| 20 | 60 | 1 | 0.02 |
| 15 | 45 | 2 | 0.04 |
| 10 | 30 | 3 | 0.10 |
| 5 | 15 | 4 | 0.27 |
[3 marks]
(ii) From the table in (f) (i) above, draw a graph of the strength of the straw against the length of the straw.
Axes – correct with the correct label and units = 1 mark
Points are correctly transferred = 1 mark
Shape of graph is correctly drawn = 1 mark. [3 marks]
g. From the graph you have drawn in (f)(ii) above, explain the relationship between the length of the straw and its strength.
When the length of the straw increases ,the strength of the straw decreases.
This is because increase in the length of the straw will increase its surface
area and thus the weight to bend it is smaller
[3 marks]
h. From the experiment, what can be deduced about the strength of the straw ?
The strength of the straw is the maximum weight it can take before it bends , when the weight is hung from its middle portion, the strength of the straw is affected by its length.
[3 marks]
i. If a same type of straw, is clamped on the same retort stands with length 20cm with the thicker wall, between the wooden blocks, predict the strength of the straw.
The strength of the rod will be stronger than 0.02 N/cm2.
This is because the straw has the same diameter and length but it has thicker wall, giving it more strength , so increasing its strength
12 June 2010
form 5 P3 Q2
Correction
Biology PKBS 2
Form 5 - Paper 3 Qn 2 (BOD).
#{ 1 time= 1 BI, 5 times = 3 BI + 2 BM , 8 times = 5 BI + 3 BM, 10 times = 6 BI + 4 BM }#
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Sample answer:
1. Problem
Statement: What is the effect of different distance between the rubber factory
and the village on the rate of water pollution?
2. Aim : To investigate the effect of the distance between the rubber factory
and the villages on the rate of water pollution.
3.Hypothesis: The longer the distance between the rubber factory and the
villanges , the lower the rate of water pollution.
4. Variables:
Manipulated V: The distance between the rubber factory and the villages.
Responding V: The rate of water pollution // The time taken for the methylene
blue solution to decolourised.
Control V: The volume of the methylene blue solution
5. Apparatus
& Materials : water samples, methylene blue solution, reagent bottle,
stop-watch, syringe, cupboard
6Technique : Record the time taken for the methylene blue solution to turn colourless
7. PRocedure:
- Water samples are taken from the river at villages P, Q and R
- 200ml of water sample from village P is transfered into the reagent bottle P.
- Using a syringe, 1ml of 1% methylene blue solution is slowly injected
into the water sample P.
- The tip of the syringe is used to stir the solution slowly.
- The bottle is capped immediately and placed in a cupboard.
- The stop watch is started.
- The reagent bottle is observed every one hour to determine whether the
methylene blue has been decolourised.
- The time taken for the methylene blue to decolourised is taken and recorded down.
- Steps 2 to 8 are repeated with the sample water from villages Q and R.
- The results are recorded in a table.
Result:
| Water sample. | Time taken for methylene blue solution to turn colourless (min) | The rate of water pollution 1/t (min-1) |
| P | | |
| Q | | |
| R | | |
Consclution : The longer the distance between the rubber factory and the villanges
, the lower the rate of water pollution. The hypothesis is accepted.
09 June 2010
Correction form 5 sc 1
Markah PKBS2 dan Pembetulan 5 SC 1
| Biology PKBS 2 / 2010 Form : 5 Sc1 SMKBS | |||
| Name | Mark | Correction | |
| P 2 | P 3 | ||
| Mohd Amin b Awang Teh | 53 | 1 | 1 |
| Mohd Aimen Afiq b Che | 80 | 1 | 1 |
| Mohd Azeem b A R | 45 | 5 | 5 |
| Mohd Adrisam b Mohd | 50 | 1 | 1 |
| Mohd Khairul Rizal | 45 | 5 | 5 |
| Muhd Nazari b Mad Zin | 32 | 7 | 8 |
| Mohd Raffi b Mohd Nawi | 48 | 5 | 5 |
| Muhd Shafiq b Mazlan | 50 | 1 | 1 |
| Wan Muhd Farhan b | 40 | 5 | 5 |
| Wan Zahir b Wan Yusoff | 65 | 1 | 1 |
| Amira bt Mohd Sudin | 43 | 5 | 5 |
| Fatin Nabila bt Abd | 53 | 1 | 1 |
| Maizatul Azma b Mazlan | 39 | 7 | 8 |
| Noor Asliza bt Ismail | 57 | 1 | 1 |
| Nur Afini bt Mohd Nor | 52 | 1 | 1 |
| Nur Ain bt Zulkifli | 48 | 5 | 5 |
| Nur Eylia bt Nazrul | 50 | 1 | 1 |
| Nur Safira bt Mohd Fazli | 65 | 1 | 1 |
| Nur Farah Aisyah | 41 | 5 | 5 |
| Nurul Syazlini bt Mahat | 46 | 5 | 5 |
| Rosmaliejan bt Alias | 49 | 5 | 5 |
| Siti Nur Amalean Ameri | 46 | 5 | 5
|
| Syafra Shah Nurul bt J | 46 | 5 | 5 |
| Note: Sila hantar pembetulan anda pada hari isnin, 21/6/10, jawapan akan diberi pada 13/6 semasa kelas tambahan. Harap maklum. Terima kasih. MO June 2010 | |||
Correction form 5 sc 2
Markah PKBS2 dan Pembetulan 5 Sains 2
| Biology PKBS 2 / 2010 Form : 5 Sc2 SMKBS | |||
| Name | Mark | Correction | |
| P 2 | P 3 | ||
| Che Muhammad b C S | 39 | 7 | 8 |
| Kharol Anuar b Ripan | F22 | 10 | 10 |
| Mohd Asri b Mohd Rapi | 44 | 5 | 5 |
| Mohd Haris b Adnan | 33 | 7 | 8 |
| Mohd Muhaimin b Abd | 44 | 5 | 5 |
| Mohd Raziff b Ramly | F25 | 10 | 10 |
| Mohd Razali b Yusoff | 35 | 7 | 8 |
| Mohd Rizwan b Mohd | F29 | 10 | 10 |
| Mohd Salahuddin b Ab | 30 | 7 | 8 |
| Mohd Shafiq Safwan b A | F26 | 10 | 10 |
| Nik Muhammad Fadhil | 44 | 5 | 5 |
| Wan Mohd Izwan WM | 43 | 5 | 5 |
| Fadilah bt Zulkifli | F24 | 10 | 10 |
| Fatin Liyana Maulad | F28 | 10 | 10 |
| Hafifah bt Sahibul Anwar | F22 | 10 | 10 |
| Najmun Khairani | F24 | 10 | 10 |
| Nadia bt Mat Daud | F29 | 10 | 10 |
| Nur Farah Amalina | 31 | 7 | 8 |
| Nur Izzati bt Rahimi | 31 | 7 | 8 |
| Nur Mas Idayu bt Zali | 35 | 7 | 8 |
| Nurul Farhanis bt Mat Rozi | 35 | 7 | 8 |
| Nurul Nabilah bt M Soud | 40 | 5 | 5 |
| Nurul Khasyhah Amyra | F18 | 10 | 10 |
| Siti Norma bt Mohd Nor | 34 | 7 | 8 |
| Siti Nurul Aida Shahrarud | F28 | 10 | 10 |
| Wan Nurshuhadah | F27 | 10 | 10 |
| Zarina bt Musa. | F27 | 10 | 10 |
| Note: Pembetulan anda akan dihantar pada hari Ahad 20/6, Jawapan akan diberi pada 13/6 semasa kelas tambahan . Terima kasih. MO June 2010 | |||