Question

Jessica stretches her arms out to 0.6m from the center of her body while holding a 2 kg mass in each hand She then spins around on an ice rink at 1.1m/s.

If she pulls her arms in to .15 m, what is her linear speed if the angular momentum remains constant?

Answer 1

4.4 m/s

Step-by-step explanation:

Angular momentum is:

L = Iω

For a point mass, this can also be written as:

L = mvr

Angular momentum is conserved, so:

L₁ = L₂

m₁ v₁ r₁ = m₂ v₂ r₂

(2 kg) (1.1 m/s) (0.6 m) = (2 kg) v (0.15 m)

v = 4.4 m/s