Lab- Response Time

 

Hypothesis: I hypothesize that humans who belong to age group 10- 25, will have a lesser reaction time when compared to humans belonging to the age groups :- below 10 and above 25.

Plan

Variables

Apparatus: -

• 1 x 30 cm ruler
• ‘Distance of ruler drop to Reaction time’ Conversion graph
• Results table
• Stool

Fig 1

Conversion graph

        

Fig 2

Method

1. Collect apparatus as shown in diagram- fig 1
2. Select 3 people of the same gender(male) but of different ages- 8 year old, 16 year old 32 year old.
3. Record their ages in the result table
4. Take the first person and place his writing hand on the corner of the stool so that his hand up to his wrist is supported by the stool and the wrist is suspended outside the stool as shown in fig 2
5. Instruct the person to hold his fingers apart in a U shape, i.e. the thumb and index while folding the other fingers
6. Hold the ruler loosely with the 0cm marking just at the same level of the thumb.
7. Leave the ruler and instruct the person to grasp it as soo as he sees it drop.
8. Observe the distance between the beginning of the ruler and the place the ruler is held and record the result in the results table.
9. Redo steps 5-8 10 times for the same person and record results.
10. Find the average of the 10 results and use the obtained value to find the “reaction time” using the conversion graph.
11. Redo steps 5-10 for all the people chosen.

Results

Results table 1

Results Table 2

Conclusion

My hypothesis was proved correct when referred to the obtained results and the above graph because humans who belong to age group 10- 25, had a lesser reaction time when compared to humans belonging to the age groups :- below 10 and above 25.

                                        Reaction Time

Below 10 years             0.22 seconds    

10-25 years                   0.20 seconds

Above 25 years             0.23 seconds

The shape of the graph was observed to be in a ‘U’ Shape which further supports my hypothesis graphically. There is no pattern or a trend observed however it can be noticed that people belonging to the age group 10-25 have the lowest reaction time, i.e. fastest reflexes.

Evaluation:

The results obtained were reliable and helped me prove my hypothesis correct. However, there were no major anomalies observed but a few minor inaccuracy errors.

• The experiment conducted was manual and therefore conducted various manual errors such as inaccurate distance measured.
• Another manual error could be that of not holding the ruler’s 0cm mark accurately at the edge of the thumb.
• The time of the day gradually increased as the experiment was conducted and therefore could not be kept as controlled variable.
• The person conducting the experiment gradually got used to the act and therefore would respond better.
• The ruler being a length of 30 cm, often was to small a reaction distance and therefore slipped out of the hand thereby giving no result.

Improvements – If I was to conduct the experiment again, I would:-

• Use a digital method to investigate the reaction time, eg- Car Brake simulation.
• Use a larger number of results resulting in an increase in the accuracy of my results.