Experimental sciences 35 Identify whether these activities would be studied in physics or chemistry: a lift going up or down making yoghurt peeling an apple eating an apple heating milk charging a battery 36 Which of these phenomena would not be studied in chemistry: a) The formation of a rainbow. b) How butane gas burns in a kitchen. c) The manufacture of a new type of plastic. d) The effects of a new drug to improve its composition. 37 Which of these phenomena would not be studied in physics: a) How a satellite moves around Jupiter. b) The forces on a suspension bridge. c) The behaviour of Iberian lynx in captivity. d) The intensity of the electric current in a circuit. 38 Read this text and answer the questions: "Do you want to talk to your ancestors? Do you want to meet your future grandchildren? Dr. Cole has achieved what science cannot explain. Do not trust nonbelievers. Experience it for yourself." a) Explain whether the text refers to science or false science. b) Why do you think they use the title "doctor"? c) Is it possible that there are some facts that science cannot explain? d) Convince a partner that the text is true or false. Use scientific reasons. 39 Which of these statements are not scientific hypotheses? Explain your answer. a) When an object is thrown upwards, the height it reaches depends on its colour. b) When an object is thrown upwards, the height it reaches depends on the initial speed of the throw. c) When an object is thrown upwards, the height it reaches is related to what the person is thinking about when it is thrown. 40 Conduct this experiment on the evaporation of water. Answer the questions in your notebook. Use a measuring cylinder to pour 50 mL of water into the following containers: a tall and narrow glass, a wide glass and a soup bowl. Leave them for three days. Then measure how much water is in each one. Calculate how much water has evaporated. a) What observation could make you think of this experiment? b) What are the variables in this experiment? c) Make a hypothesis. d) Study the results. Write the law that can be concluded from the data. 41 Identify the statement that is a law of physics. a) How much a spring stretches does not depend on its colour. b) The acceleration of an object is directly proportional to the force we apply on it, and inversely proportional to its mass. c) All young people like the colour red more than green. 42 This graph represents the distance travelled by an object moving in a straight line and the time taken. Explain whether the statements below are correct. d (m) t (s) 0 1 2 3 4 5 0 5 10 15 20 25 a) W hen the time is doubled, the distance travelled is also doubled. b) As time increases, the distance travelled decreases. c) The distance travelled between seconds 3 and 4 is greater than the distance travelled between seconds 1 and 2. c h e c k yo u r p r o g r e s s 30
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