Is my elbow the point of application of force of a torque?

In summary, when you pick up a bucket, you apply a force to it through the Centre of Mass (CoM) of the bucket. Your elbow acts as a fulcrum while your biceps muscle contracts, putting force on the tendon that attaches it to the radius bone in your forearm. This results in your hand rising and lifting the bucket through the bail handle. The point of application of force is at the insertion of the biceps brachii muscle on the radius bone, not at the shoulder or near the shoulder. This makes the lower arm a class 3 lever.
  • #1
David lopez
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if i pick up a bucket i apply torque to the bucket. my shoulder is the fulcrum. is my elbow the point of application of force? just trying to understand the physics?
 
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  • #2
David lopez said:
if i pick up a bucket i apply torque to the bucket. my shoulder is the fulcrum. is my elbow the point of application of force? just trying to understand the physics?
Normally when you pick up a bucket you apply a force to the bucket (through the CoM - Centre of Mass - of the bucket), but no torque about the CoM.
 
  • #3
David lopez said:
if i pick up a bucket i apply torque to the bucket. my shoulder is the fulcrum. is my elbow the point of application of force? just trying to understand the physics?
If you lift a bucket, there are at least two levers in operation.

Let us suppose that you have grabbed the bucket by its bail handle. The bucket is currently on a table in front of you. Your upper arm is near vertical and your lower arm is extended in front of you to the bucket.

You lift the bucket. Your elbow joint is acting as a fulcrum. Your biceps muscle is contracting, putting a large force on the tendon that attaches it to the radius bone in your forearm. Your hand rises as a result and the bail handle provides the load against which your hand lifts.

Considering the lower arm only, that makes this a class 3 lever.
 
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  • #4
jbriggs444 said:
If you lift a bucket, there are at least two levers in operation.

Let us suppose that you have grabbed the bucket by its bail handle. The bucket is currently on a table in front of you. Your upper arm is near vertical and your lower arm is extended in front of you to the bucket.

You lift the bucket. Your elbow joint is acting as a fulcrum. Your biceps muscle is contracting, putting a large force on the tendon that attaches it to the radius bone in your forearm. Your hand rises as a result and the bail handle provides the load against which your hand lifts.

Considering the lower arm only, that makes this a class 3 lever.
so where would the application of force be?
 
  • #5
David lopez said:
so where would the application of force be?
At the point where the biceps tendon attaches to the radius.

You can find an image here.
 
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  • #6
so at the shoulder or near the shoulder?
 
  • #7
David lopez said:
so at the shoulder or near the shoulder?
No. Not at the shoulder. Not near the shoulder. At the point where the biceps meets the radius. The point labeled "Insertion of the Biceps Bracchi". We are considering the lower arm as the lever.
 

Related to Is my elbow the point of application of force of a torque?

1. What is a torque?

A torque is a measure of the force that causes an object to rotate around an axis. It is calculated by multiplying the force applied to an object by the distance from the axis of rotation.

2. How is torque related to my elbow?

Your elbow is the point of application of force for a torque when you are using your arm to rotate or move an object. The force applied by your muscles creates a torque at your elbow, causing your arm to rotate.

3. Can I change the point of application of force for a torque?

Yes, you can change the point of application of force for a torque by moving your arm or changing the position of your hand. This will change the distance from the axis of rotation, affecting the torque applied to the object.

4. What factors affect the magnitude of torque at my elbow?

The magnitude of torque at your elbow is affected by the force applied by your muscles, the distance from your elbow to the axis of rotation, and the angle at which the force is applied. Increasing any of these factors will increase the torque at your elbow.

5. How does torque affect my everyday movements?

Torque plays a role in many everyday movements, such as lifting objects, throwing a ball, or even opening a door. It is what allows us to rotate our arms and move objects with precision and control. Understanding torque can also help prevent injuries by using proper technique and distributing force effectively.

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