(g) State an example of how neutralisation is used in our daily life. Antacids are used to neutralise the excess acid in our stomach to help relieve the discomfort. (or any other suitable answer) [1 mark] 6. The figure shows some odd-looking rocks in Utah, USA. This is due to weathering. (a) What is weathering? It is the breaking down of rocks on the surface of the Earth. [1 mark] (b) State the three types of weathering. Physical weathering, biological weathering and mechanical weathering [3 marks] (c) (i) Which type of weathering gives the rocks the funny shapes as shown above? Physical weathering [1 mark] (ii) Briefly describe how it happens. The strong wind carries sand particles that hit the rocks. The soft parts of the rocks are broken off, leaving the rocks with funny shapes. [2 marks] (d) How does weathering differ from erosion? Weathering is the breakdown of rocks into smaller pieces. Erosion is the transport of weathered rocks to other places. [1 mark] 7. The displacement-time graph below is for a wave. Time / s Displacement / cm 2 2 –2 4 6 8 148 ©Praxis Publishing_Focus On Science
(a) How many complete cycles are shown here? 2 [1 mark] (b) (i) What does period mean? What is its unit? Period is the time taken for a wave to make one complete cycle. Its unit is second (s). [2 marks] (ii) What is the period of the wave shown in the graph? 4 s [1 mark] (c) (i) What does frequency mean? What is its unit? Frequency is the number of complete cycles made by a wave in a second. Its unit is Hertz (Hz). [2 marks] (ii) How are frequency and period related to each other? Frequency = 1 Period or Period = 1 Frequency [1 mark] (iii) What is the frequency of the wave? 0.25 Hz [1 mark] (d) (i) What does amplitude mean? What is its unit? Amplitude is the maximum displacement of the vibrating particle from its equilibrium point. Its unit is metre (m). [2 marks] (ii) What is the amplitude of the wave? 2 cm [1 mark] 8. Azmin lives in a small town in Turkiye. On 6 February 2023, he felt a strong tremor in his house and quickly ran outside. The tremor shook his house causing some damages but Azmin survived. Assessment 2 149 ©Praxis Publishing_Focus On Science
(a) What is an earthquake? It is the movement of the Earth’s surface when a sudden release of energy in the Earth’s lithosphere occurs. [1 mark] (b) (i) Azmin later heard that the epicentre of the earthquake was 150 km away from his town. What is an epicentre? It is a point on the Earth’s surface directly above the point inside the Earth’s crust where the energy is released. [1 mark] (ii) Predict the damage to his house if his house is situated very near to the epicentre. His house might collapse and turn into rubble. [1 mark] (c) Azmin also found out that the earthquake had a magnitude of 7.8. How is the magnitude of an earthquake measured? What is the scale used? Using a seismograph. The scale used is Richter scale [2 marks] (d) Indonesia is also prone to earthquakes. Explain why. It is situated on the earthquake belt. This zone has active tectonic plates. [1 mark] (e) On 26 December 2004, an earthquake occurred in the seabed off Banda Aceh. It caused a tsunami that washed away many structures and people in Banda Aceh. (i) What is a tsunami? It is a series of huge waves due to earthquakes under the sea. [1 mark] (ii) Why did a tsunami not occur in Turkiye during its earthquake in 2023? In Turkiye, the epicentre of the earthquake is on land, not in a seabed. The earthquake only caused a vigorous shaking to the Earth’s surface. As there was no seawater, no seawater was displaced to cause a tsunami. [2 marks] 150 ©Praxis Publishing_Focus On Science
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