A 5-kg shark swimming at 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the shark after his meal is
A) 1/2 m/s.
B) 1/5 m/s.
C) 1/6 m/s.
D) 2/3 m/s.
E) 3/2 m/s.
Question 2
A 5000-kg freight car moving at 2 m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at
A) 2 m/s.
B) 1 m/s.
C) 2/3 m/s.
D) 1/3 m/s.