- #1
bionut
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A 35N hand and forearm are held at a 45 degree angle to the vertically oriented humerus. The centre of gravity of the forearm and hand is located at a distance of 15cm from the joint centre at the elbow, and the elbow flexor muscle attach at an average distance of 3cm from the joint centre. How much force must be exerted by the forearm flexors to maintain this position?
Okay this is my attempt at the question:
Wt= 35N
dwt=0.15m
df=0.03m
fm(sin45) x (0.03m) = (35N) X (0.15m)
fm (0.02) = 5.25
fm= 262.5
Rv= 262.5 sin 45 - 35N
Rv=185.62 - 35
Rv=150.62
Rh= 262.5 Cos 45
Rh= 185.62
R= SqRoot (185.62)sqr + (150.62)sqr
R=239.04 N
But my answer is wrong can anyone see where I went wrong? My answer should be 192.5
Okay this is my attempt at the question:
Wt= 35N
dwt=0.15m
df=0.03m
fm(sin45) x (0.03m) = (35N) X (0.15m)
fm (0.02) = 5.25
fm= 262.5
Rv= 262.5 sin 45 - 35N
Rv=185.62 - 35
Rv=150.62
Rh= 262.5 Cos 45
Rh= 185.62
R= SqRoot (185.62)sqr + (150.62)sqr
R=239.04 N
But my answer is wrong can anyone see where I went wrong? My answer should be 192.5