Answer:
4.92 m/s for her final velocity.
Step-by-step explanation:
The momentum of the skater before throwing the stone is:
p1 = m1 * v1 = 50 kg * 5 m/s = 250 kg*m/s
where m1 is the mass of the skater and v1 is her initial velocity.
When the skater throws the stone, the total momentum of the system (skater + stone) is conserved. The momentum of the stone is:
p2 = m2 * v2 = 2 kg * 2 m/s = 4 kg*m/s
where m2 is the mass of the stone and v2 is its velocity.
Let's assume the skater throws the stone in front of her. To conserve momentum, the skater will move in the opposite direction to the stone. Let's call the skater's final velocity v3. Then:
p1 = p2 + p3
where p3 is the momentum of the skater after throwing the stone. Substituting the values we get:
250 kgm/s = 4 kgm/s + 50 kg * v3
Solving for v3, we get:
v3 = (250 kgm/s - 4 kgm/s) / 50 kg = 4.92 m/s
So the skater's speed after throwing the stone in front of her is 4.92 m/s.
If the skater throws the stone behind her, the same conservation of momentum principle applies, and we get the same result of 4.92 m/s for her final velocity.
Sorry if I'm wrong