Question

# Biomedical measurements show that the arms and hands together typically make up 13.0 %% of a...

Biomedical measurements show that the arms and hands together typically make up 13.0 %% of a person's mass, while the legs and feet together account for 37.0 %%. For a rough (but reasonable) calculation, we can model the arms and legs as thin uniform bars pivoting about the shoulder and hip, respectively. Let us consider a 70.0 kgkg person having arms 66.0 cmcm long and legs 95.0 cmcm long. The person is running at 12.0 km/hkm/h, with his arms and legs each swinging through ±30∘±30∘ in 12s12s. Assume that the arms and legs are kept straight.

What is the average angular velocity of his arms and legs?

Using the average angular velocity from Part A, calculate the amount of rotational kinetic energy in this person's arms and legs as he walks.

What is the total kinetic energy due to both his forward motion and his rotation?

What percentage of his kinetic energy is due to the rotation of his legs and arms?

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