Soalan Fokus Spm 2009 Set 3 (ans)

Soalan Fokus SPM 2009 Set 3 1.

Diagram 5.1 and 5.2 show two watermelons fall off a table and drop on to surface A and surface B respectively. Rajah 5.1 dan 5.2 menunjukkan dua biji tembikai jatuh dari sebuah meja ke atas permukaan A dan permukaan B masing-masing.

Permukaan A Surface A

Diagram 5.2 Rajah 5,2

Diagram 5.1 Rajah 5.1 (a).

Surface B Permukaan B

What is meant by impulse? Apakah yang dimaksudkan dengan impuls? Change of momentum

(b)

……………………………………………………………………………… [1 mark] With reference to Diagram 5.1 and Diagram 5.2, Merujuk kepada Rajah 5.1 dan Rajah 5.2, (i)

Compare the force on the watermelons that strike on Surface A and Surface B. Bandingkan daya pada tembikai yang menghentam ke atas Permukaan A dan Permukaan B. Force on the watermelon in Diagram 5.1 is larger than the force on the ……………………………………………………………………… watermelon in Diagram 5.2

[1 mark]

(ii)

Compare the time of impact of the watermelons on Surface A and Surface B. Bandingkan masa hentaman tembikai itu pada Permukaan A dan Permukaan B. Time of impact on surface A is shorter than time of impact on surface B

(iii).

……………………………………………………………………… [1 mark] State the relationship between the force produced in a collision and the time of impact. Nyatakan hubungan antara daya yang dihasilkan dalam suatu perlanggaran dengan masa hentaman. A shorter time of impact will produce a larger force.

……………………………………………………………………… [1 mark] 1

(c)

Mark with a (√ ) for the correct statement about the change of momentum of the watermelons in both situations above. Tandakan (√ ) pada pernyataan yang betul mengenai perubahan momentum pada tembikai dalam dua situasi di atas. The change of momentum of the watermelon in Diagram 5.1 is greater than that of the watermelon in Diagram 5.2. Perubahan momentum pada tembikai dalam Rajah 5.1 adalah lebih besar daripada tembikai dalam Rajah 5.2. The change of momentum of the watermelon in Diagram 5.2 is greater than that of the watermelon in Diagram 5.1. Perubahan momentum pada tembikai dalam Rajah 5.2 adalah lebih besar daripada tembikai dalam Rajah 5.1. _/

The change of momentum of the watermelon in Diagram 5.1 is equal to that of the watermelon in Diagram 5.2. Perubahan momentum pada tembikai dalam Rajah 5.1 adalah sama dengan tembikai dalam Rajah 5.2. [1 mark]

(d)

Suggest a suitable material for surface B. Cadangkan satu bahan yang sesuai bagi permukaan B. Sponge/ towel/ cloth ……………………………………………………………………………… [1 mark]

(e)

Diagram 5.3

By referring to the Diagram 5.3, explain how the driver is able to avoid serious injuries when the car stopped suddenly. Rujuk pada Rajah 5.3, terangkan bagaimana pemandu itu dapat mengelakkan kecederaan yang parah ketika kereta berhenti dengan tiba-tiba. Body will be hold back by the seat belt when the car stopped suddenly ……………………………………………………………………………… The seat belt will be lengthen slightly, the impulsive force acting on the ……………………………………………………………………………… body will be less.

……………………………………………………………………………… 2

[2 marks]

2.

Diagram 11.1 shows two boats of the same weight floating on the surface of water in the sea and in the river. Rajah 11.1 menunjukkan dua buah kapal berjisim sama , terapung di permukaan sungai dan di permukaan laut.

Boat in the sea Bot di dalam laut

Boat in the river Bot di dalam sungai Diagram 11.1

(a)

(i)

What is meant by weight? Apakah yang dimaksudkan dengan berat? Weight is the gravitational force acts on an object

(ii)

[1 mark]

Explain why the boat is able to float? Terangkan kenapa kapal itu boleh terapung? Upthrust = Weight of the boat

[1 mark] Explain why the sinking levels of the boats are different in the river and in the sea. Terangkan kenapa paras kapal yang tenggelam berbeza di dalam sungai dan di dalam laut? Sea water is denser, Boat displaced less sea water, therefore boat sinks less in the sea water [3 marks] (b) If the volume of the boat that sinks in sea water is 250 m3 and the density of sea water is 1080 kgm-3, calculate Jika isipadu kapal yang tenggelam dalam air laut ialah 250 m3 dan ketumpatan air laut adalah 1080 kgm-3, kirakan (iii)

(i)

upthrust which acts on the boat. tujahan yang bertindak ke atas kapal.

Upthrust = weight of sea water displaced = mg = vρ sea water g = 250 x 1080 x 10 = 2.7 x 106 N

(ii)

[3 marks]

the volume of water displaced when the boat is in the river. [Density of river water = 1000 kgm-3] isipadu air yang disesarkan apabila kapal itu berada dalam sungai. [Ketumpatan air sungai = 1000 kgm-3] [2 marks] 3

Upthrust = Weight of river water 2.7 x 106 = mg m =v ρriver waterg

(c)

v =2.7 x 106 /1000 x 10 v = 270 m3

Diagram 11.2 shows the specifications of four hydrometers P, Q, R and S. Rajah 11.2 menunjukkan keterangan-keterangan bagi empat hydrometer P, Q, R dan S.

Diagram 11.2 You are asked to measure the density of and acid solution. 4

Anda ditugaskan untuk mengukur ketumpatan suatu larutan asid.

3.

(i)

Study hydrometers P,Q,R and S in diagram 11.2 and explain the suitability of each features to determine the density of acid solution. Kaji semua hydrometer P,Q,R dan S dalam rajah 11.2 dan terangkan kesesuaian setiap binaan bagi hidrometer yang akan diguna untuk mengukur ketumpatan suatu larutan asid.

(ii)

Determine the most suitable hydrometer to be used to measure the density of an acid solution. Tentukan hirometer yang paling sesuai untuk digunakan bagi menyukat ketumpatan suatu larutan asik. [10 marks]

Radioactive material has some important uses in the field of agriculture such as to study the effectiveness of fertilizers and control the population of pests. Bahan radioaktif mempunyai beberapa kegunaan penting dalam bidang pertanian seperti mengkaji keberkesanan baja dan pengawalan populasi serangga. (a)

A researcher conducted an investigation using posphorus-32 to study the absorption and movement of fertilizers in the plant. Diagram 12.1 shows how radioisotope posphorus-32 is injected to the stem of the plant. The half-life of posphorus-32 is 14 days and emits β-particles. Seorang penyelidik telah menjalankan satu penyiasatan menggunakan fosforus-32 untuk mengkaji penyerapan dan pergerakan baja dalam satu tumbuhan .Rajah 12.1 menunjukkan bagaimana fosforus-32 disuntik kedalam batang tumbuhan itu. Separuh hayatbagi fosforus-32 ialah 14 hari dan memancarkan zarah-β.

Diagram 12.1 Based on the information on radioactivity and Diagram 12.1 : Berdasarkan maklumat dalam keradioakifan dan Rajah 12.1: (i)

What is meant by half life? The time taken for half of nucleus of radioactive material to decay

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Apakah yang dimaksudkan dengan separuh hayat? [1 mark] (ii)

What is β-particles. Apakah zarah-β. Fast moving electron

(iii)

[1 mark]

Name the most suitable detector could be used to detect βparticles. Namakan satu alat pengesan yang paling sesuai digunakan untuk mengesan zarah-β. Geiger-Muller tube

(b)

[1 mark]

The initial posphorus-32 activity is 800 counts per second. Calculate the time taken for the phosphorus-32 activity to decrease to 50 counts per second. Keaktifan awal fosforus-32 ialah 800 bilangan per saat. Hitung masa yang diambil untuk keaktifan fosforus-32 berkurang menjadi 50 bilangan per saat. [2 marks] 800 -------> 400 ------> 200 ------> 100 ------> 50 Time taken = 4 x 14 days = 64 days

(c)

The population of pests can be controlled using radiation from radioactive source. You are assigned to study the characteristics of some radioisotopes that are suitable for use in controlling the population of pests. Table 12.2 shows the characteristics of four radioisotopes. Populasi serangga dapat dikawal dengan menggunakan sinaran radioaktif dari satu sumber radioaktif. Anda ditugaskan untuk mengkaji ciri-ciri bagi beberapa radioisotope yang sesuai untuk digunakan dalam mengawal populasi serangga. Jadual 12.2 menunjukkan ciri-ciri bagi empat radioisotop.

Radioisotope Radioisotope

Characteristics of radioisotope Ciri-ciri radioisotop State of matter Keadaan jirim

Types of ray Jenis sinar

Half-life Separuh hayat

Iodine-131 Iodin-131

Liquid Cecair

Gamma Gama

8 days 8 hari

Xenon-133 Xenon-133

Solid pepejal

Beta Beta

5 days 5 hari

Cobalt-60 Kobalt-60

Solid Pepejal

Gamma Gama

5 years 5 tahun 6

Strontium-90 Strontium-90

liquid cecair

Beta Beta

8 years 8 tahun

Table 12.2 Explain the suitability of the characteristics of the radioisotope to be used in the controlling the population of pests based on the following aspects: Terangkan kesesuian ciri-ciri radioisotope untuk digunakan dalam mengawal populasi serangga berdasarkan aspek-aspek berikut: -

State of matter Keadaan jirim

-

Types of ray Jenis sinar

-

Half-life Separuh hayat

Determine the most suitable radioisotope to be used and give the reason for your choice. Tentukan radioisotope yang paling sesuai digunakan dan beri sebab bagi pilihan anda. [8 marks] (c)

The following equation shows a fission reaction of Uranium-235. Persamaan berikut menunjukkan satu persamaan tindakbalas pembelahan nukleus Uranium-235.

(i)

What is meant by a nuclear fission? Apakah yang dimaksudkan dengan pembelahan nucleus? The process of breaking up on heavy nucleus into lighter nucleus

(ii)

[1 mark]

Nuclear fission produces a chain reaction. Describe how the chain reaction occurs in a nuclear fission of an atom of Uranium- 235. Pembelahan nukleus menghasilkan tindakbalas berantai. Huraikan bagaimana tindakbalas berantai berlaku dalam pembelahan satu atom uranium-235. [4 marks]

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1. Neutron bombarded a uranium nucleus 2. Three neutrons, two stable nucleus produced. 3. The new neutron bombarded a new uranium nucleus. 4. For every chain reaction, a huge nuclear energy will produced.

(iii)

The nuclear energy produced in the fission reaction of uranium235 is 2.9 x 10-11 J. Calculate the total lost of mass in the reaction. [ c = 3.0 x 108 ms-1] Tenaga nuklear yang dihasilkan dalam tindakbalas pembelahan itu ialah 2.9 x 10-11 J. Hitungkan jumlah kehilangan jisim dalam tindakbalas itu [ c = 3.0 x 108 ms-1] [2 marks] [2 markah]

E=4.mc2 s -11 8 2 -28 m 5. = E/c2 =2.9 s x 10 /(3.0 x 10 ) =3.22 x 10 kg

6. s 7. ss Answer (b): 8. of matter s - State is solid 9. to shandle -Easier 10. s - Emits gamma ray - Penetrating power is high - Long half life - Last longer - The most suitable is cobalt -60 -because the state of mater is solid, emit gamma ray and long half life.

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