Chapter 10

Question 1

Rigid bar (bone) that moves a fixed point of a fulcrum (joint)

Answer 1

Lever

Question 2

Force applied (supplied by muscle contraction) to lever to move resistance (load)

Answer 2

Effort

Question 3

Resistance (bone + tissue + added weight) moved by effort

Answer 3

Load

Question 4

Power lever
Load is close to fulcrum, effort far from fulcrum
Small effort can move large load

Answer 4

Mechanical advantage

Question 5

Speed lever
Load is far from fulcrum, effort closer to fulcrum
Load moved rapidly over large distance
Wide range of motion

Answer 5

Mechanical disadvantage

Question 6

Load-fulcrum-effort
Can be mechanical advantage or disadvantage
Ex. Seesaw or scissors
Ex. Lifting head off chest

Answer 6

First-class lever

Question 7

Fulcrum-load-effort
Mechanical advantage
Ex. Standing on toes
Ex. Wheelbarrow

Answer 7

Second-class lever

Question 8

Fulcrum-effort-load
Mechanical disadvantage
Ex. Skeletal muscles (bicep curls)
Ex. Tweezers

Answer 8

Third-class lever