Conservation of Momentum of roller-skates

[HeyyMarco]

Homework Statement

Anthony and Sissy are participating in the "Roll-a-Rama" roller-skating dance championship. While 75kg Anthony roller-skates backwards at 3m/s, 60kg Sissy jumps into his arms with a velocity of 5m/s in the same direction.
m1= 75kg
v1= 3m/s
m2= 60kg
v2= 5m/s
v' = ?

Homework Equations

The inelastic collision equation possibly?

The Attempt at a Solution

(75kg)(3m/s) + (60kg)(5m/s)= (75kg+60kg)x
225kg*m/s + 300kg*m/s= 135kg(x)
525kg*m/s = 135kg(x)
(525kg*m/s)/135kg = x
3.8m/s= x

Is that correct?

 

[ehild]

Yes, it is inelastic collision and your calculation is correct, but take care of rounding. x=3.888... round it to 3.9 m/s.

ehild

 

[HeyyMarco]

Yes, it is inelastic collision and your calculation is correct, but take care of rounding. x=3.888... round it to 3.9 m/s.

ehild

Thank you very much :)