whats the best way to solve this physics question??

Question

To get off a frozen, frictionless lake, a 70.0 kg person takes off a 0.150 kg shoe and throws it horizontally, directly away from the shore with a speed of 2.00 m/s. If the person is 5.00 m from the shore, how long does it take for him to reach it?

Answer 1

Conservation of momentum...

70kg * v = 0.15kg * 2
v = 0.0043 m/s

about 20 min.