The momentum of an object is given by the product between its mass and its velocity:

where m is the mass and v the velocity.
For the object in our problem, m=10 kg and v=10 m/s, therefore its momentum is

So, the correct answer is B).
Answer:
2.84 seconds
Explanation:
t = ?
distance = 125
Velocity origianal = 60 m/hr = 88 ft/s
AVERAGE velocity = 88/2 = 44 ft/s
44 t = 125
t = 125/44 = 2.84 s