a 65-kg ice skater moving to the right with a velocity of 2.50m/s throws a .150kg snowball to the right with a velocity of 32.0m/s relative to the ground

a) what is the velocity of the ice skater after throwing the snowball?
b) a second skater initially at rest with a mass of 60kg catches the snowball. What is the velocity of the second skater after catching the snowball?

3 answers

m1=65 kg, m2 =0.15 kg, m3 = 60 kg,
v1 = 2.5 m/s, v2 = 32 m/s.

(m1 + m2)•v1 =m2•v2 + m1•u,
u = {(m1+m2) •v1 – m2•v2}/m1 = {65.15•2.5 -0.15•32}/65 = 2.43 m/s,

m2•v2 = (m2+m3) •u1,
u1 = m2•v2/(m2+m3) = 0.15•32/(60+0.15) =
= 0.08 m/s.
I’m concerned what u mean by adding the letter “u” in this equation
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