Problem 7.33 An athlete at the gym holds a 1.5kg steel ball in his hand. His arm
ID: 1284092 • Letter: P
Question
Problem 7.33
An athlete at the gym holds a 1.5kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg .
Part A
What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor?
Express your answer to two significant figures and include the appropriate units.
Part B
What is the magnitude of the torque about his shoulder if he holds his arm straight, but 60? below horizontal?
Express your answer to two significant figures and include the appropriate units.
Explanation / Answer
If parallel;
T=F.d.sina sin=>between angle Force and Distance vector
T=1,5 .9,8 .0,7 + 4. 9,8. 0,35
If straight;
sin0=0 so there is no torque angle zero.
if angle 60;
T=F.d.sin60
T=1,5 .9,8 .0,7.sin60+4. 9,8. 0,35.sin60