LATIHAN TITIAN CEMERLANG CHAPTER 2 : FORCE AND MOTION2 Diagram 2 shows a bag of cement of mass 35 kg on a ramp with 15o slope to horizontal. Frictional force exerted between the bag and the ramp is 90.6 N. Rajah 2 menunjukkan sekampit simen di atas landas condong dengan kecondongan 15o terhadap ufuk. Daya geseran yang bertindak di antara kampit dan landas condong itu ialah 90.6 N. Trg: Paper 2 Diagram 2 Rajah 2 (a) What is meant by frictional force? Apakah yang dimaksudkan dengan daya geseran? .................................................................................................................................................. (b) Calculate the resultant force parallel to the ramp. Hitungkan daya paduan selari dengan landas condong itu. [1 mark] (c) Based on your answer in (b), explain what happens to the motion of the bag of cement? Berdasarkan jawapan anda dalam (b), terangkan apakah berlaku pada gerakan kampit simen itu? …………………………………………………………….………………………………….. ………………………………………………………………………………………………... [2 marks] [2 marks] 9 Diagram 9 shows a ball placed onto smooth incline plane at point P. The ball is rolling down Trg:Paper 2 over he incline plane caused by gravitational potential energy. Point Q and point R are at the middle of the incline plane and at the ground respectively. Rajah 9 menunjukkan sebiji bola diletakkan di atas satah condong yang licin di titik P. Bola itu bergolek turun di atas satah condong itu disebabkan oleh tenaga keupayaan graviti. Titik Q dan titik R adalah masing-masing di tengah satah condong itu dan di tanah. Diagram 9 Rajah 9 (a) What is meant by gravitational potential energy? [ Apakah yang dimaksudkan dengan tenaga keupayaan kenyal? (b) (i) Using Diagram 9, compare the height of the ball, the gravitational potential energy of the ball, the velocity of the ball and the kinetic energy of the ball at point P and point Q. Deduce the relationship between the kinetic energy and the gravitational potential energy of the rolling ball. Menggunakan Rajah 9, bandingkan ketinggian bola itu, tenaga keupayaan kenyal bola itu, halaju bola itu dan tenaga kinetik bola itu pada titik P dan titik Q. Rumuskan hubungan di antara tenaga kinetik dengan tenaga keupayaan kenyal bola yang bergolek itu. [1 mark] [5 marks] (ii) Name the physical principle involved in (b)(i). Namakan prinsip fizik yang terlibat dalam (b)(i). (c) Explain what happens to the velocity of the ball when it reaches point R on the ground. Terangkan apa yang terjadi kepapa halaju bola itu apabila ia sampai pada titik R di atas tanah. [1 marks] [3 marks] (d) Based on the physical principle above, you are required to design a roller skate track. Using appropriate physics concept, explain the design of the roller skate track so that it can be used to oscillate skate board continuously. Your answer should include the following aspects: Berdasarkan prinsip fizik di atas, anda diminta untuk merekabentuk trek papan peluncur. Menggunakan konsep fizik yang sesuai, terangkan rekabentuk trek papan peluncur yang dapat digunakan supaya papan peluncur boleh berayun berterusan. Jawapan anda hendaklah merangkumi aspek-aspek berikut: (i) Shape of the track Bentuk trek (ii) Slope of the track Kecondongan trek (iii) Surface of the track Permukaan trek (iv) Safety. Keselamatan. [10 marks] 7 Diagram 7 shows an electric motor lifting a 2.0 kg load. When the motor is switched on, the load moved through a height of 1.5 m in 2.5 s with constant speed. The current flowing in the circuit is 1.7 A and the potential difference across the motor is 10.0 V. Rajah 7 menunjukkan sebuah motor elektrik sedang mengangkat satu beban 2.0 kg. Apabila motor itu dihidupkan, beban itu bergerak melalui ketinggian 1.5 m dalam 2.5 s dengan laju malar. Arus yang mengalir dalam litar ialah 1.7 A dan beza keupayaan merentasi motor itu ialah 10.0 V. Ked: paper 2 Diagram 7 / Rajah 7 (a) State the changes in energy that occur when the motor is switched on. Nyatakan perubahan tenaga yang berlaku apabila motor itu dihidupkan. ……………………………………………………………………………………… (b) Calculate, Hitung, (i) the electrical power supplied when the motor is lifting the load. kuasa elektrik yang dibekalkan semasa motor itu mengangkat beban. [1 mark] (ii) the output power of the motor when the load moved through a height of 1.5 m in 2.5 s. kuasa output motor apabila beban itu melalui ketinggian 1.5 m dalam 2.5 s. [2 marks] (iii) the efficiency of the electric motor. kecekapan motor itu. [2 marks] (c) If some of the load is removed while the motor is still lifting the load, what change is observed on the ammeter? Explain your answer. Jika sebahagian daripada beban dikeluarkan semasa motor itu mengangkat beban, apakah perubahan yang diperhatikan pada ammeter? Jelaskan jawapan anda ……………………………………………………………………………………… ……………………………………………………………………………………… (d) Suggest one way to increase the efficiency of the motor. Cadangkan satu cara untuk menambah kecekapan motor itu. ……………………………………………………………………………………… [2 marks] [2 marks] [1 mark] 7 . Diagram 7 shows a spring. Rajah 7 menunjukkan satu spring. Kel: Paper 2 Diagram 7 Rajah 7 (a) When a load is attached to the spring ; Apabila satu beban dilekatkan pada spring ; (i) What happen to the length of the spring? Apakah yang berlaku pada panjang spring? ……………………………………………………………………………... (ii) What is the energy stored in the spring? Apakah tenaga yang tersimpan dalam spring? ……………………………………………………………………………... [1 mark] [ 1 mark] (iii) If the number of load is increased, what will happen to the energy in 7 a(ii)? Jika bilangan beban ditambah, apakah yang akan berlaku kepada tenaga di 7 a(ii)? …………………………………………………………………………..…. [ 1 mark] (b) The initial length of a spring is 15 cm. When a load with mass 300g is attached to the spring, the length of the spring is 21 cm. Panjang asal spring adalah 15 cm. Apabila beban berjisim 300g dilekatkan pada spring. panjang spring adalah 21 cm. What is the length of the spring if a load with mass 500g is attached to the spring? Berapakah panjang spring jika beban berjisim 500g dilekatkan pada spring? [ 3 marks] (c) The spring in Diagram 7 is not suitable to be used as a spring cradle. Suggest modifications to be done based on the characteristics given below. Spring dalam Rajah 7 tidak sesuai digunakan untuk spring buaian. Cadangkan pengubahsuaian-pengubahsuaian yang perlu dilakukan berdasarkan ciri-ciri yang diberi di bawah. (i) Arrangement of the springs Susunan spring …………………………………………………..………………………… (ii) Reason Sebab ……………………………………………………………………………... (iii) Stiffness of the spring Kekerasan spring ……………………………………………………………………………... (iv) Reason Sebab ……………………………………………………………………………... [1 mark] [1 mark] [1 mark] [1 mark] Ked :Paper 2 8 Diagram 8 shows the graph of force against extension for three springs P, Q and R. Rajah 8 menunjukkan graf daya melawan pemanjangan bagi tiga spring P, Q dan R. Diagram 8 / Rajah 8 (a) (i) A law states that the extension of a spring is directly proportional to the force applied if the elastic limit of the spring is not exceeded. Name this law. Suatu hukum menyatakan bahawa pemanjangan seutas spring adalah berkadar terus dengan daya yang dikenakan jika had kenyal tidak dilebihi. Nyatakan hukum ini. …...................................................................................................................... [1 mark] (ii) On the graph in Diagram 8, mark ' X ' at the elastic limit for each spring. Pada graf dalam Rajah 8, tandakan ' X ' pada had kenyal setiap spring. (b) The spring stores energy when it is extended. Spring itu menyimpan tenaga apabila diregang. [2 marks] (i) Name the energy stored in the spring when it is extended. Namakan tenaga yang disimpan dalam spring yang diregang. …...................................................................................................................... [1 mark] (ii) Calculate the energy stored in spring R when its extension is 8.0 cm. Hitung tenaga yang disimpan dalam spring R apabila pemanjangannya 8.0 cm. [3 marks] (c) The springs are to be used in a Newton balance to measure a maximum load of mass 8 kg. Spring-spring tersebut akan digunakan di dalam neraca Newton untuk mengukur beban maksimum berjisim 8 kg. (i) What is the maximum weight of the load? Berapakah berat maksimum beban itu? …...................................................................................................................... (ii) Based on Diagram 8, choose two springs which are suitable to be used in the Newton balance specified above. Berdasarkan Rajah 8, pilih dua spring yang sesuai untuk digunakan di dalam neraca Newton tersebut di atas. …...................................................................................................................... (iii) Which spring is the most suitable to be used in the Newton balance? Explain your answer. Spring yang manakah paling sesuai untuk digunakan di dalam neraca Newton itu. Terangkan jawapan anda. …...................................................................................................................... …...................................................................................................................... [2 marks] [1 mark] [2 marks] 9 Diagram 9.1 shows a stationary pistol on a smooth surface. KED: Diagram 9.2 shows the pistol and bullet after the pistol has been fired by remote Paper 2 control. Rajah 9.1 menunjukkan sebuah pistol pegun di atas permukaan licin. Rajah 9.2 menunjukkan pistol dan peluru selepas tembakan dilepaskan secara kawalan jauh. Diagram 9.1 / Rajah 9.1 Diagram 9.2 / Rajah 9.2 (a) (i) What is the meaning of momentum? Apakah maksud dengan momentum? [1 mark] (ii) State the total momentum of the pistol and bullet in Diagram 9.1 Using Diagram 9.1 and Diagram 9.2, compare the total momentum before and after the bullet is fired. Using Diagram 9.2, compare the magnitude and direction of the momentum of the bullet and pistol. Name the physics principle that can be applied to the motion of the bullet and pistol. Menggunakan Rajah 9.1 dan Rajah 9.2, bandingkan jumlah momentum sebelum dan selepas peluru itu ditembak. Menggunakan Rajah 9.2, bandingkan magnitud dan arah momentum peluru dan pistol. Nyatakan prinsip fizik yang boleh diaplikasi kepada gerakan peluru dan pistol itu. [5 marks] (b) Describe, in terms of momentum, the propulsion of a rocket engine. Terangkan, dalam sebutan momentum, rejangan sebuah enjin roket. [4 marks] (c) Diagram 9.3 shows a the structure of a jet engine for a small jet plane. Rajah 9.3 menunjukkan struktur sebuah enjin jet bagi sebuah kapal terbang jet yang kecil. Diagram 9.3 / Rajah 9.3 You are required to give some suggestions to improve the design of the jet engine so that it can be used on a larger jet plane that travels at a higher speed. Using the knowledge on forces and motion and the properties of materials, explain the suggestions based on the aspects labeled on Diagram 9.3 Anda dikehendaki memberi beberapa cadangan untuk membaiki reka bentuk enjin jet itu supaya enjin jet itu boleh digunakan pada sebuah kapal terbang jet yang lebih besar dan bergerak lebih laju. Menggunakan pengetahuan tentang gerakan, daya dan sifat-sifat bahan terangkan cadangan itu yang merangkumi aspek-aspek yang dilabel pada Rajah 9.3. [10 marks]