Torque of human arm when bending

AI Thread Summary
The discussion focuses on calculating the torque required to bend a human arm at various angles (180°, 90°, and 30°) without holding any weight. The relevant torque equation is τ = rFsinθ, where the total arm weight is 3.35 kg, with an upper arm length of 19 cm and a forearm length of 28 cm. Participants emphasize the need to clarify the orientation of the upper arm for accurate calculations, particularly for the 180° bend. There are requests for clearer presentation of attempted calculations and equations. The conversation highlights the complexity of the problem and the importance of precise inputs for torque determination.
mdp_somebodeh
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To find the respective torque that is need to bend the the arm at 180 degrees, 90 degrees and 30 degrees. The arm is not holding anything.

Relevant equations and information
τ=rFsinθ

total arm weight =3.35kg
upper arm length =19cm
forearm length =28cm
 
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welcome to pf!

hi mdp_somebodeh! welcome to pf! :wink:

show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:

(start with 180°)
 
This is bending at the elbow, right? Don't you need to know the orientation of the upper arm?
 
sorry, too difficult to read :redface:

can you type it out, please? :smile:​
 
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