contestada

06

Some students investigated the effect of drinking caffeine on reaction time.

They used a drink containing 32. 25 mg of caffeine per 100 cm

This is the method used.

1. Divide the students into four groups, A, B, C and D.

2. Measure and record the reaction time of each student using the ruler-drop test.

3. Students in:

• group A drink 200 cm of water

• group B drink 200 cm of the caffeine drink

• group C drink 400 cm of the caffeine drink

• group D drink 600 cm of the caffeine drink.

4. Repeat step 2 after 15 minutes.

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6

1

Describe how to do the ruler-drop test.

[3 marks]