Distance (m) Time (s) 0.25 0.33 0.50 0.48 0.75 0.59 1.00 0.69 Ball A: 50 g 3.5. Analyse the results: tables and graphs The hy pothesis must be tr ue under d i f ferent cond itions. Therefore, severa l exper iments are usua l ly conducted and lots of data is col lected. Tables and g raphs ma ke it easier to organ ise and ana lyse the resu lts. Graphs prov ide a v isua l representat ion of the data . For example, they show the relat ionsh ip bet ween t wo va r iables. Tables a l low us to arrange data in rows and columns. Each column conta ins the data for a va r iable. Each row conta ins the va lues for each va r iable. 5 The var iables in ex per iment 2 a re d istance and t ime. The unit of measu rement is in brackets. What can we conclude f rom these tables? The t ime it ta kes the ba l ls to fa l l does not depend on thei r mass. The t ime increases w ith the d istance travel led . I f the d istance is doubled , the t ime increases but by less than double. What can we conclude f rom the g raph? The g reater the d istance travel led , the longer the ba l l ta kes. Time and d istance a re not d i rect ly propor t iona l . The ba l l ta kes longer to travel 1 m than 0. 5 m, but not t w ice as long. Draw a g raph for ba l l A 1. Draw two axes. Each axis represents a quantity. Write the name or symbol of the quantity on each axis. 3. Represent each pair of values with a point on the graph. 2. Taking into account the minimum and maximum values in the table, write the scale of each axis. The scales of the two axes are not related. 4. Draw a line to show the trend. Some points can be above or below the line. Distance (m) Time (s) 0.25 0.33 0.50 0.47 0.75 0.58 1.00 0.71 Ball B: 37 g Distance (m) Time (s) 0.25 0.34 0.50 0.48 0.75 0.59 1.00 0.70 Ball C: 22 g Each row has the resu lts for one measurement. 3. Application of the scientific method 1.00 0.75 0.50 0.25 0.00 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 d (m) t (s) The line of best fit can be straight or curved. 1.25 Interpolate Find values between the ones we measured. How long will it take to travel 0.45 m? Extrapolate Find values outside the range we measured. How long will it take for the ball to travel 1.25 m? 16
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