Question

n which of the following cases is the torque about the shoulder due to the weight of the arm the greatest? Case 1: A person holds her arm at an angle of 30o above the horizontal (hand is higher than shoulder). Case 2: A person holds her amr straight out parallel to the ground. Case 3: A person holds her arm at an angle of 30o below the horizontal (hand is lower than shoulder).

Answer 1

Answer:

Case 2: A person holds her amr straight out parallel to the ground.

Explanation:

As we know that

Torque Τ given as

T = r x F

T = F r sinθ

θ =Angle between force and distance from force .

If the angle is maximum then the sinθ will be maximum it means that at θ = 90° the torque T will be maximum.

So the case 2 is correct.

Case 2: A person holds her amr straight out parallel to the ground.