How Does Throwing a Partner Affect a Skater's Velocity in a Pairs Competition?

[Mrchilko]

Homework Statement

In a pairs skating competition, the male skater is initially carrying his partner. Together they have a mass of 130.0 kg and they are are moving forward with a velocity of 2.5 m/s. If the male skater throws his partner forward at 1.5m/s, find the velocity of the male skater after he throws his 45.0kg partner.

Homework Equations

P_a + P_b = P'_a + P'_b

v= p/m

The Attempt at a Solution

So assuming the equation to find velocity which is v=p/m all i have right now is the mass of the male skater which is 85kg. Now I am not to sure what to do with the original combined momentum ( both skaters together) which was p= (130kg)(2.50m/s)= 325kg.m/s... Now would what do i do with that do find the answer?

 

[mfb]

Now I am not to sure what to do with the original combined momentum ( both skaters together) which was p= (130kg)(2.50m/s)= 325kg.m/s

You know it is conserved, you can apply that to find a condition on the final velocities. The other condition is given in the problem statement.

 

[gneill]

So assuming the equation to find velocity which is v=p/m all i have right now is the mass of the male skater which is 85kg. Now I am not to sure what to do with the original combined momentum ( both skaters together) which was p= (130kg)(2.50m/s)= 325kg.m/s... Now would what do i do with that do find the answer?

You have more than just the mass of the male skater. You have the total momentum, and you have the mass and velocity of the thrown skater (assuming the thrown velocity is with respect to the ice rink and not the male skater).

 

[haruspex]

assuming the thrown velocity is with respect to the ice rink and not the male skater

Considering the numbers given, that would not be my assumption.