For each group: 

1 meter stick

1 $1 bill

Answer Key:

1.)

 
 

2.) Convert distance dropped to meters: 3" = 0.0762 m 

The time it takes to fall 3" is 0.124 seconds. 
 
 

3.) Catch at 0.21 m:

t _reaction= 0.207 seconds 

4.) 

t_impulse = 1/7 second 

t_impulse = 0.143 seconds to catch the dollar bill 

5.)

t_impulse = 0.143 seconds

t_reaction = 0.207 seconds

t_fall = 0.124 seconds

Since t_impulse and t_reaction  are both greater than   t_fall, it is impossible to catch the dollar bill.