1) hickory dickory dock, the 20.0-g mouse ran up the clock, and took turns riding on the 0.20-m-long second hand, the 0.20-m-long minute hand and the 0.10-m-long hour hand. what was the angular momentum of the mouse on each of the three hands? 2) in a physics experiment, ingrid, the ice skater, spins around in the rink at 1.2 m/s with each of her arms stretched out 0.70m from the center of her body. in each hand she holds a 1.0kg mass. if angular momentum is conserved, how fast will ingrid beging to spin if she pulls her amrs to a position 0.15m from the center of her body?

1a) Angular momentum of the mouse on the second hand:

The angular momentum of the mouse is given by:

where

m = 20.0 g = 0.02 kg is the mass of the mouse

v is the speed of the mouse

r = 0.20 m is the length of the hand

The speed of the mouse is equal to the length of the circumference divided by the time taken to complete one circle (60 s):

So the angular momentum is

1b) Angular momentum of the mouse on the minute hand:

In this case, the mouse takes to complete one circle, so the speed of the mouse is

So, the angular momentum is

1c) Angular momentum of the mouse on the hour hand:

In this case, the mouse takes to complete one circle, so the speed of the mouse is

So, the angular momentum is

2) New speed of Ingrid: 5.6 m/s

The initial angular momentum of Ingrid is twice the momentum produced by each mass:

Angular momentum must be conserved, so the final momentum must be the same when the arms are pulled to a new length of r'=0.15 m, so we find:

unlike poles attract