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## Homework Statement

A merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg m2. The merry-go-round is initially at rest. A 20 kg child is running at 5.0 m/s along a line tangent to the rim. Find the angular velocity of the merry-go-round after the child jumps on.

a. 0.38 rad/s

b. 0.45 rad/s

c. 0.71 rad/s

d. 0.56 rad/s

e. 1.2 rad/s

## Homework Equations

p(angular)=Iω

p=mv

p(angular)=p*r

## The Attempt at a Solution

i tried to use conservation of momentum by saying:

r*mv+0=(I+mr)ω

and i got ω=0.45 but the answer key says the answer is a. 0.38 rad/s