A 45kg skater and a 60kg skater are standing still, holding hands on frictionless ice. They push away from each other in opposite directions. If the 45kg skater was measured traveling at 3.5 m/s, how fast was the 60 kg skater traveling?

The 60 kg skater is traveling at 2.63 m/s in the opposite direction from the 45 kg skater.

Explanation:

The velocity of the 60 kg skater can be found by conservation of linear momentum:

 (1)

Where:

: is the mass of the first skater = 45 kg        

: is the mass of the second skater = 60 kg        

: is the initial speed of the first skater = 0 (he is standing still)

: is the initial speed of the second skater = 0 (he is standing still)

: is the final speed of the first skater = 3.5 m/s

: is the final speed of the second skater =?

By replacing the above values into equation (1) and solving for we have:

The minus sign is because the 60 kg skater is moving in the opposite direction from the other skater.

Therefore, the 60 kg skater is traveling at 2.63 m/s in the opposite direction from the 45 kg skater.

I hope it helps you!