When a gymnast weighing 740 N executes the iron cross as in figure (a), the primary muscles involved in supporting this position are the latissimus dorsi ("lats") and the pectoralis major ("pecs"). The rings exert an upward force on the arms and support the weight of the gymnast. The force exerted by the shoulder joint on the arm is labeled Fs while the two muscles exert a total force Fm on the arm. Determine the magnitude of the force Fm. Note that one ring supports half the weight of the gymnast, which is w = 370 N as indicated in figure (b). Assume that the force Fm acts at an angle of 45° below the horizontal at a distance of 4.0 cm from the shoulder joint. In your estimate, take the distance from the shoulder joint to the hand to be L = 71 cm and ignore the weight of the arm.
Rotational Equilibrium And Rotational Dynamics
In physics, the state of balance between the forces and the dynamics of motion is called the equilibrium state. The balance between various forces acting on a system in a rotational motion is called rotational equilibrium or rotational dynamics.
Equilibrium of Forces
The tension created on one body during push or pull is known as force.
When a gymnast weighing 740 N executes the iron cross as in figure (a), the primary muscles involved in supporting this position are the latissimus dorsi ("lats") and the pectoralis major ("pecs"). The rings exert an upward force on the arms and support the weight of the gymnast. The force exerted by the shoulder joint on the arm is labeled
while the two muscles exert a total force
on the arm. Determine the magnitude of the force
Note that one ring supports half the weight of the gymnast, which is w = 370 N as indicated in figure (b). Assume that the force
acts at an angle of 45° below the horizontal at a distance of 4.0 cm from the shoulder joint. In your estimate, take the distance from the shoulder joint to the hand to be L = 71 cm and ignore the weight of the arm.
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