A 60-Kg Ball Is Held in the Hand with the Lower

question 31

Multiple Choice

A 6.0-kg ball is held in the hand with the lower arm making a 90-degree angle with the upper arm. The lower arm and hand have a combined mass of 2.5 kg and a center of mass 18 cm from the elbow joint. The ball is 40 cm from the elbow joint. If the biceps muscle is 12 cm from the center-of-mass point of the lower arm and hand, calculate the force that the biceps muscle must exert in order to keep the lower arm and hand horizontal.

• A) 466 N
• B) 48.0 N
• C) 392 N
• D) 233 N
• E) none of the above

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Definitions:

Schaie's Perspective

Refers to the theoretical framework proposed by K.Warner Schaie regarding the sequential stages of cognitive development throughout the adult lifespan.

Cognitive Development

Refers to the process by which individuals acquire and develop the ability to think, reason, and understand over the course of their lives.

Dualistic Thinking

Dualistic thinking is the tendency to divide information, values, and perspectives into polar opposites, often ignoring complexities or middle grounds.

Schemes

Cognitive structures or patterns of behavior through which individuals process and understand their environment.