Posted by **Christina** on Monday, April 14, 2008 at 6:00pm.

A 22.8 kg turntable with a radius of 47 cm

is covered with a uniform layer of dry ice

that has a mass of 4.08 kg. The angular

speed of the turntable and dry ice is initially

0.52 rad/s, but it increases as the dry ice

evaporates.

What is the angular speed of the turntable

once all the dry ice has evaporated? Answer

in units of rad/s. 1.0 m

- Physics -
**drwls**, Monday, April 14, 2008 at 6:27pm
You are probably suppoased to assume that the turntable is frictionless and "coasting" (unpowered) while the dry ice evaporates. This is a rather unrealistic assumption

Anyway, in that case, you should assume that angular momentum is conserved.

I1 w1 = I2 w2.

If the dry ice is evenly distributed, the moment of inertia I is proportional to total mass, M. Therefore

M1 w1 = M2 w2.

w2 = (22.8)/(22.8-4.7) x 0.52

- Physics (corrected) -
**drwls**, Monday, April 14, 2008 at 6:29pm
You are probably supposed to assume that the turntable is frictionless and "coasting" (unpowered) while the dry ice evaporates. This is a rather unrealistic assumption

Anyway, in that case, you should assume that angular momentum is conserved.

I1 w1 = I2 w2.

If the dry ice is evenly distributed, the moment of inertia I is proportional to total mass, M. Therefore

M1 w1 = M2 w2.

w2 = [(22.8 + 4.7)/(22.8)] x 0.52

- Physics -
**bobpursley**, Monday, April 14, 2008 at 6:30pm
If you model the turntable-ice mixture, then the moment of inertia will be proportional to mass.

wf=Iinitial/I final* wi

=k(4.08+22.8)/k(22.8) * .52 rad/sec

## Answer This Question

## Related Questions

- physics - A turntable must spin at 33.7 rpm (3.53 rad/s) to play an old-...
- Physics - A 25.0-g metal cylinder is placed on a turntable, with its center 70 ...
- physics - A 21.0-g metal cylinder is placed on a turntable, with its center 85 ...
- Physics - A 21.0-g metal cylinder is placed on a turntable, with its center 90 ...
- Physics - A large turntable rotates about a fixed vertical axis, making one ...
- Physics - A large turntable rotates about a fixed vertical axis, making one ...
- Physics - A turntable of radius 2m rotates freely about a fixed vertical axis. A...
- Physics HELP! - A coin rests 18.0 cm from the center of a turntable. The ...
- Physics URGENT!!! - A coin rests 18.0 cm from the center of a turntable. The ...
- physics - A coin rests 15.0 cm from the center of a turntable. The coefficient ...

More Related Questions