posted by stacy .
Emily challenges her husband, David, to catch a $1 bill as follows. She holds the bill vertically, with the center of the bill between David's index finger and thumb. David must catch the bill after Emily release it without moving his hand downward. If his reaction is 0.2 s, will he succeed? Explain your reasoning.
The bill is about 7 cm. high.
So David has to catch it before it falls through 7cm, assuming David's fingers are right below Emily's.
initial velocity, u =0
Solve for t to see if it exceeds 0.2 s.