Jessica stretches her arms out 0.6 m from the center of her body while holding a 2 kg mass in each hand. she then spins around on an ice rink at 1.1 m/s. a. what is the combined angular momentum of the masses? b. if she pulls her arms in to 0.15m, what is her linear speed if the angular momentum remains constant?

a.

r = distance of each mass from the axis of rotation = 0.6 m

m = magnitude of each mass = 2 kg

v = speed of each mass = 1.1 m/s

combined angular momentum of the masses is given as

L = m v r + m v r

L = 2 m v r

inserting the values

L = 2 (2) (1.1) (0.6)

L = 2.64 kg m²/s

b.

r' = new radius  around the axis of rotation = 0.15 m

v' = new speed

using conservation of angular momentum

angular momentum after pulling arms = angular momentum before pulling arms

L' = L

2 m v' r' = 2 m v r

v' r' = v r

v' (0.15) = (1.1) (0.6)

v' = 4.4 m/s

a displacement distance is size of displ