The displacement of a moving object is the straight-line distance between the place it starts from and the place where it stops.
The displacement of anything moving along a circular track depends on how far around it goes before it stops. The greatest displacement it can possibly have is the diameter of the track ... 100m on this particular one ... because that's as far apart as two places on a circle can ever be.
The most interesting case is when the object goes around the circle exactly once. Then it stops at the same place it started from, the distance between the starting point and ending point is zero, and after all that motion, the displacement is zero.
Apply the law of conservation of momentum for this situation. The law states that the momentum of a system is constant (in absence of external forces acting on it).
The 'system' in this case are the two skaters. There is no external force on the skaters. Suppose the skaters are initially standing still. The momentum in the system is 0. This value will need to remain constant, even after the mutual push (which is a set of forces from <em>inside</em> the system). So we know that
(total momentum before) = (total momentum after)
Indexing the masses and velocities by the first letter of the skaters' names:

From the last row, you can see that the skaters will have momentum of same magnitude but opposite direction, after the push off. That answers the first question: neither will have a greater momentum (both will have one of same magnitude).
Since Ricardo is heavier, from the above equality it follows that

In words, Paula has the greater speed, after the push-off.
Answer:
-35 m/s
Explanation:
Momentum is conserved.
Momentum before firing = momentum after firing
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
Before the bullet is fired, the bullet and rifle have no velocity, so u₁ and u₂ are 0.
0 = m₁v₁ + m₂v₂
Given m₁ = 0.7 kg, v₁ = 350 m/s, and m₂ = 7 kg:
0 = (0.7 kg) (350 m/s) + (7 kg) v
v = -35 m/s
The rifle recoils at 35 m/s in the opposite direction.
Well minerals are in the water we drink every Day, even the food we eat. Minerals are contained in rocks so there for both are important to life