An ant with mass 0.15 g lands on one end of a floating 4.75 g stick. After sitting at
rest for a moment, it runs toward the other end with a speed of 3.8 cm/s relative to
the river. What is the speed of the stick if it moves in the opposite direction?
A) 0.20 cm/s
B) 0.16 cm/s
C) 0.12 cm/s
D) 0.10 cm/s
momentum is conserved;
.15*3.8=4.75*V
V= you do it.