CH 7: Biomechanics

Question 1

The point at which both body mass and weight are equally distributed is known as what?

Answer 1

center of gravity

Question 2

With regard to stress from mechanical loading, the term shearing refers to what?

Answer 2

cutting or breaking

Question 3

how are mechanics divided into?

Answer 3

two parts: static and dynamic. static is at rest or w/o acceleration, but may still be in motion. Dynamic is w/acceleration creating uneven forces on the body

Question 4

list the 3 types of levers, the element in the middle of each, and examples

Answer 4

1st class lever - fulcrum in the middle. Seesaw/neck

2nd class lever: Load in the middle, wheelbarrow or soleus creating plantar flexion

3rd class lever: effort in the middle, tweezers, elbow flexion with bicep providing the effort

Question 5

what’s the first law of inertia?

Answer 5

body in motion stays in motion, body at rest stays at rest

Question 6

what’s the 2nd law of inertia?

Answer 6

1) change in acceleration of mass occurs in the same direction as the force causing it

2) change in acceleration is DIRECTLY proportional to the force causing it and INVERSELY proportional to the mass of the body (in other words, the more sth weighs the less acceleration; the less sth weighs the more acceleration)

Question 7

what’s the 3rd law of inertia?

Answer 7

for every action, there’s an equal and opposite reaction