A man in a gym is holding an 8.0-kg weight at arm's length, a distance of 0.55 m from his shoulder joint. What is the torque about his shoulder joint due to the weight if his arm is horizontal?
A) 43 N · m
B) 0.24 N · m
C) 4.4 N · m
D) 15 N · m
E) 0 N · m

Question

Quizplus · Accepted Answer

The torque (τ) can be calculated using the formula τ = rFsinθ, where r is the distance from the pivot point (0.55 m), F is the force applied (weight of the object, which is mass times the acceleration due to gravity, 8.0 kg * 9.8 m/s^2), and θ is the angle between the force direction and the arm (90 degrees, so sinθ = 1). Thus, τ = 0.55 m * 8.0 kg * 9.8 m/s^2 = 43.12 N·m, which rounds to 43 N·m.

A Man in a Gym Is Holding an 8