# B Arm-wrestling -- question about forces

1. Jan 2, 2018

### Luigi Fortunati

In the arm-wrestling, when the hand A prevails on the hand B, the force of A on B is greater than that of B on A?

2. Jan 2, 2018

### Orodruin

Staff Emeritus
No. That would violate Newton's third law. The torque on the arm of B from the force from A is greater than the torque on the arm of B that B is able to generate.

3. Jan 2, 2018

4. Jan 2, 2018

### Luigi Fortunati

OK thanks.

Therefore the force exerted by the hand A (also of the strongest man in the world) on the hand B, can never exceed (not even a little) the strength that the hand B exerts on the hand A (therefore represents its maximum limit).

5. Jan 2, 2018

### Orodruin

Staff Emeritus
“Strength” is not a standard physics concept. Do not confuse it with force, which is.

6. Feb 27, 2018

### CWatters

I think you need to distinguish between the muscular force and the total force one hand exerts on the other.

For example.. the force B exerts on A could stay the same even if B gives up and stops pushing. If A keeps pushing with the same force then when B gives up hand B will start accelerating and that will make up for the loss of muscular force B was applying on A.

In practice hand A won't be able to maintain the same force on B for very long but while it can hand B will exert the same force on A. Eventually he table will get in the way or hand A will be power limited (power = force * velocity and the velocity is increasing).