Question

Two kids on roller skates standing facing each other. They push off one another and travel in on opposite directions. If the boy has mass of 60 kg and is going 5.6m/s and the girl is going 7.1 what is the mass of the girl?

Answer 1

Answer: 37.326 kg

Explanation:
KE = 1/2 mv2,
1/2 m1(v1i)2 + 1/2 m2(vi)2 = 1/2 m1(v1f)2 + 1/2 m2 (v2f)
0.5*60*(5.6)^2 = 0/6*x*(7.1)^2
x = 37.3259