F

1
(No Transcript)
2
R
T
F
3
R

• Forces generated on the foot while a 150 lb man
  is standing (on 2 legs)? Determine F
• What is tension generated in achilles tendon
  (connected to gastronemius muscle) during 2
  legged stance? Determine T

T
150
1.5
6
F
F
F
4
R

• What is tension generated in achilles tendon
  (connected to gastronemius muscle) during 2
  legged stance? Determine T

T
1.5
6
75 lbs
5

• 2 legged stance
• 300 lbs of load through gastroc and tendon
• Difference between tendons and ligaments?
• Tendon will stretch-by how much? What do we need
  to calculate strain?

6
0.8 kg/mm2 would cause 3.5 elongation Cant
find a modulus and use Hookes law-why?
7

• In fact, s-e curve is
• nonlinear
• Age
• Health
• Rate of test
• ?? others
• Steel and Aluminum are linear elastic
• What is force (F) and amount of stretch (e) if we
  jump?

Fast
Slow
8

• flex our knees and push generating a rxn on our
  feet (F1)and momentum has to change
• Momentum
• Newton said external forces can change momentum
  and called it an Impulse
• Need to find velocity

9

• Jump- raising our potential energy
  but..conservation of energy we must generate
  kinetic energy
• , where g32 ft/s2 and he jumped 2 ft
• So,
• F1
• F1
• So, 175 due to impulse and 150 due to weight,
  assuming 2 legged jump

10

• F
• Go back to FBD,
• Now what is stretch of tendon

150 175
F
F
11
1.8 kg/mm2 would cause 6 elongation Tendons can
fail around 10 strain
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)