3. Application of the scientific method 3.1. Observe the phenomenon We ana lyse a phenomenon by using our senses. Through obser vation, we identif y a problem and we ask questions about it . 3.2. Search for information Many quest ions a l ready have an answer. Therefore, we need to f ind relevant informat ion on the subject . 3.3. Make a hypothesis A f ter ident i f y ing the problem and ask ing quest ions, the nex t step is to tr y to f ind answers by ma k ing a hy pothesis. Hy potheses a re g uesses about why rea l events happen. They have to be tested . It is not va l id : it is a quest ion. 8 Observe different objects in free fall. a) What questions would you ask about them? b) Where would you look for information about objects in free fall? 9 Make a hypothesis about the relationship between the mass of an object and how it falls. What experiments would you conduct to test your hypothesis? 10 Apply all the steps in the scientific method to the phenomenon chosen in the challenge. a) What data have you measured in your experiment? b) Why do you think you need to organise the data and make graphs? 11 How would you tell people in your area about the results of your experiment? Obser ve how d i f ferent objects fa l l . Def ine the problem: Not a l l objects fa l l in the same way. Ask quest ions: Why do some objects fa l l faster than others? Why do some objects fa l l in a stra ight l ine but others look l i ke they f loat dow n? Using h is intu it ion, A r istot le sa id that heav ier objects fa l l faster. Many yea rs later, Ga l i leo sa id that a l l objects fa l l at the same speed , i f a i r resistance is ig nored . He d id va r ious ex per iments to prove it . The hy potheses of ou r study a re: " The g reater the mass of an object , the faster it w i l l fa l l when it is d ropped ." " The g reater the mass of an object , the stra ighter its trajector y w i l l be in f ree fa l l ." 1 2 3 Conditions for a valid hypothesis It must be a clear and precise statement. We must be able to test it to prove it is true or false. Aristotle and Galileo: two scientists in action! Does sleeping for f ive hou rs damage the bra in? There are identica l planets to the Earth in other Solar Systems. It is not va l id : it cannot be tested . CHALLENGE 14
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