A student is sitting in a chair with nearly frictionless rollers. Her homework bag is in an identical chair right beside her. The chair and the bag havera combined mass of 20 kg. The
student and her chair have a combined mass of 65 kg. If she pushes her homework bag away
from her at 0.060 m/s relative to the floor, what will be the student's velocity immediately
after the interaction ? (Show your work)

-0.018 m/s

Explanation:

Momentum is conserved.

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Both masses start at rest, so u₁ = u₂ = 0 m/s.

0 = m₁v₁ + m₂v₂

0 = (20 kg) (0.060 m/s) + (65 kg) v₂

v₂ ≈ -0.018 m/s

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