Question

a 45 kg ice skater is traveling at 7.5 m/s collides with a 60-kg ice skater. their bodies get tied up after the collision, and they slide down the ice at the same speed. what speed are they moving after the collision?

Answer 1

By applying the conservation of momentum for the collision of a 45 kg ice skater moving at 7.5 m/s with a 60-kg stationary ice skater, we determine that their combined speed after the collision is 3.22 m/s.

Step-by-step explanation:

When a 45 kg ice skater traveling at 7.5 m/s collides with a stationary 60-kg ice skater, and they move together after the collision, we can use the conservation of momentum to determine their speed post-collision. Since the collision is perfectly inelastic (they stick together), we can set the total momentum before the collision equal to the total momentum after the collision.

Momentum before collision = Momentum after collision

(45 kg × 7.5 m/s) + (60 kg × 0 m/s) = (45 kg + 60 kg) × final velocity

338.25 kg·m/s = 105 kg × final velocity

Final velocity = 338.25 kg·m/s / 105 kg = 3.22 m/s

So, the speed at which they are moving after the collision is 3.22 m/s.