Question

An individual has a forearm length that places a 25 kg weight 32 cm from the elbow while being held in the hand. The biceps tendon attaches to the radius 4 cm from the elbow. How much force must the flexor group produce to move the weight?

Answer 1

Force need F2 = 2000 N

Explanation:

Given:

Weight F1 = 25 kg = 25 x 10 = 250 N

Length L1 = 32 cm

Add new length = 4 cm

Net momentum = 0

Find:

Force need F2

Computation:

F2L2 - F1L1 = 0

F2(4) - (250)(32) = 0

F2(4) - 8000 = 0

F2(4) = 8000

F2 = 8000 / 4

F2 = 2000

Force need F2 = 2000 N