1. Reaction Time Mini-Lab

2. Can you catch a dropped dollar?

3. Rules This is a 2 partner project
One partner holds a flat dollar bill above the outstretched 2nd and 3rd finger of their partner’s hands
The bottom of the bill should be less than an inch above the tops of the fingers
The fingers should be stretched as far apart as possible

4. Without warning, drop the bill through the partner’s open fingers
Without warning, drop the bill through the partner’s open fingers. Repeat 5-10 times.
How many times does the partner catch the dollar?
Does it matter which set of fingers the bill is dropped through?
Why is it difficult for people to catch the dollar?

5. Reaction Time
There is always a delay between seeing an occurrence and reacting to it

6. Measuring reaction time
Tools: ruler , 2 partners
Procedure:
Same setup before, replacing dollars with rulers
Make sure bottom of ruler starts immediately above the opening between fingers
Drop ruler a number times, recording the length of the ruler that passes through the fingers in cm and meters
Record 5 results dropping ruler between thumb and 2nd finger, Record 5 more between 2nd and 3rd finger.

7. Questions What is the only significant force on ruler as it drops?
What acceleration will the ruler have once it leaves the hand that drops it
What is the ruler’s initial velocity?
What value does the ruler measure?
What equation will be used to solve for the time the ruler is falling through the air (the reaction time)?

8. Lab sheet Title of the mini-lab Purpose of the lab
Data and calculations of lab (show one example)
Conclusions, Error examination

9. Causes of acceleration of the dollar or ruler

10. Acceleration is caused by an unbalance of forces applied to an object
This results in a change of motion

11. Definition of a force

12. Types of forces

13. Units of forces

14. Balanced and unbalanced forces

15. Laws governing forces at everyday speeds