A man is holding a 5.0 kg suitcase at arm's length, a distance of 0.4 m from his shoulder. What is the torque on the shoulder joint if his arm is 30° below the horizontal?

Question

Quizplus · Accepted Answer

The torque ($\tau$) can be calculated using the formula $\tau = rF\sin(\theta)$, where $r$ is the distance from the pivot point (0.4 m), $F$ is the force applied (weight of the suitcase, $mg$, where $m = 5.0\, \text{kg}$ and $g = 9.8\, \text{m/s}^2$), and $\theta$ is the angle between the force direction and the arm (30° below the horizontal means the angle with the vertical is 60°). Thus, $\tau = 0.4 \times 5.0 \times 9.8 \times \sin(60°) \approx 17.0\, \text{N}\cdot\text{m}$.

A Man Is Holding a 5