An athlete at the gym holds a 4.33 kg steel ball in his hand. His arm is 75.0 cm long and has a mass of 5.28 kg. What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor?

Responses

Physics - bobpursley, Saturday, October 11, 2008 at 9:36pm
The torque has to be the weight of the ball x distance plus the weight of the arm x 1/2 the length of the arm(assuming the cg is at the midpoint).

Is distance 0.75 m?

1 answer

What distance? The arm length is 0.75 m, but half of that is 0.375 m

If you want torque in units of Newton-meters, the lengths must be in meters when you do the calculation