Question

While doing her crossfit workout, Yasmeen holds an 7.0 kg weight at arm's length, a distance of 0.57 m from her shoulder joint. What is the torque about her shoulder joint due to the weight if her arm is horizontal? A 30 N m B. 4.0 N m C. 43N-m D. 39 N m

Answer 1

Answer:

D. 39 N m

Explanation:

m = mass of the weight used in crossfit workout = 7.0 kg

Force due to the weight used is given as

F = mg

F = (7.0) (9.8)

F = 68.6 N

d = distance of point of action of weight from shoulder joint = 0.57 m

τ = Torque about the shoulder joint due to the weight

Torque about the shoulder joint due to the weight is given as

τ = F d

Inserting the values

τ = (68.6) (0.57)

τ = 39 Nm