Measure Equipment METHOD How c Ontrol Dependent independent
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Measure Equipment METHOD How? c. Ontrol Dependent/ independent variables
Measure: What are you going to measure? e. g. temperature change? How long it takes for something to occur? Voltage? Equipment: What equipment will you need? What is the role of each piece? Method: Step-by-step how will you carry out the experiment? If you are timing something, how long for? If you are measuring something, how long? What units? How will you know if the reaction has worked? If your hypothesis is correct? Control: Which variables are you controlling? Are you using a control as a comparison? What are you measuring (dependant)? What is it you're changing in the experiment? (independent)
The effect light intensity has on the rate of photosynthesis Measure: The number of bubbles produced over 2 minutes Equipment: Lamp, metre ruler, stopwatch, beaker, test tube, water, Elodea Method: 1) Set up as shown In diagram 2) Count how many bubbles are produced at 100 cm away from Elodea…. . How: Where more bubbles are given off, photosynthesis is being carried out at a faster rate. Control: Same lamp, same plant UV light so heat isn’t a factor on rate. Dependant: What are you measuring - the number of bubbles produced in 2 minutes Independent what are you changing – the distance the lamp is from the plant
Effect caffeine has on reaction time Measure: What are you measuring? What are you looking to find out? Equipment: What equipment will you need to work out the effect caffeine has on reaction times? Are you given some already? Method: Step by step how will you carry out your experiment? How will you know if caffeine has had an effect on reaction times? Control – One person was asked not to have any caffeine as a control. Explain the use of the control in this situation What are you measuring (dependant)? What is it you're changing in the experiment? (independent)
The liquid with the highest viscosity will slow the ball down the most. How long it takes for a ball to move through liquids of different viscosities. 1) Hold ball above glycerol, ensure stopwatch is ready Stopwatch, 6 x test tubes, petrol, washing up liquid, water, glycercol, vegetable oil, testube rack, ball The ball used will be the same. Same volume of liquid. Same sized test-tube. Same stopwatch used. time it takes for a ball to move through different objects We are changing the liquids used as they have different viscosities