# Spinning flywheel in suitcase

1. Nov 29, 2013

### M.Jenniskens

1. The problem statement, all variables and given/known data
A famous practical joke makes use of a suitcase, inside which is mounted a flywheel which is rapidly spinning about a horizontal axis. Describe what a porter experiences when he tries to turn the corner carrying the suitcase. If the flywheel has a mass of 5 kg, a radius of gyration of 20 cm, and is spinning at 600 rpm, suggest a way the porter should carry the suitcase to be able to go round a right-angled bend in just 3 seconds.

2. Relevant equations
torque=(moment of inertia)(angular acceleration)
moment of inertia=(radius of gyration)^2(mass)

3. The attempt at a solution
Please see attached file for my solution. I think I have the description of what the porter experiences correct but i don't no about the rest.

!!Thanks!!

#### Attached Files:

• ###### CAP_1996 Q3.docx
File size:
38 KB
Views:
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2. Nov 30, 2013

### Simon Bridge

Have you ever tried the demonstration where you sit on a swivel chair and hold a bicycle wheel by the axle?
Someone spins the wheel up, and you turn the wheel while it is spinning?

How about the one where the wheel precesses?

If so, then you should be able to relate what you've done to those experiences.
If not, then you need need the experience. There should be videos of this.

Last edited by a moderator: Sep 25, 2014
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