There's a chopstick on my hand. I need to find the 'angles'.

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Homework Statement


Known:
- Mass of the chopstick
- Gravity

Homework Equations


ed0ec2ed1783f9c2654b4acf7d432bec.png

c22e37af0377d584aea9ff3cfadf7332.png

8fd728988b0b1704566656584a280601.png


So the alpha(angular acceleration) can be found

The Attempt at a Solution


By knowing angular acceleration, I successfully wrote a program that simulate a chopstick falling onto my hand. But all of this is assuming my hand didn't move at all. Currently in my simulation, only the gravitational force affect the angle change (angular acceleration).

My question:
How my hand affect the angular acceleration?
I have these data:
- My hand's acceleration in x, y and z axis.
 
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Discussion

Welcome to PF!

Hi lgmcben! Welcome to PF! :wink:

Your hand will exert a force F, which wiill increase the linear acceleration by F/m, and will also add a torque. :smile:
 


Hi. Thank you for your answer. =)

tiny-tim said:
Hi lgmcben! Welcome to PF! :wink:

Your hand will exert a force F, which wiill increase the linear acceleration by F/m,

I'm sorry I forgot to mention that I want to omit any linear translation in this simulator ^_^; I only need to simulate the angular-related translations.


I have one more question:
tiny-tim said:
and will also add a torque. :smile:

Does this torque equal to
c22e37af0377d584aea9ff3cfadf7332.png

Where
F = ma
and
m = mass of the chopstick
a = acceleration of my hand in x axis? (if x, y and z axis is too much, then let's talk about only x-axis for now)

Thank you again!
 
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Yes it does equal to the above specified equation. However, you will need to consider torquing about the centre of mass in the chopsticks if the pivot points are anything except the middle of the chopsticks (assuming mass to be equally distributed and the chopsticks to be rectangular prisms)