Biomechanics - Lever Systems

Question 1

Centre of mass

Answer 1

The point at which a body is balanced in all directions

The point from which weight appears to act

Question 2

Stability

Answer 2

•The ability of a body to resist motion and remain at rest

Question 3

Functions of lever systems

Answer 3

• To generate muscular effort to overcome a given load

* To increase the speed of a given moment

Question 4

Component parts of a lever system

Answer 4

• Lever (bone)
• Fulcrum (joint)
• Effort (muscular force)
• Load (weight or resistance)

Question 5

First class levers

Answer 5

Effort and load either side of the fulcrum in the middle

E - F - L

Question 6

Example of first class levers

Answer 6

Extension of the neck when preparing to head a football

Question 7

Second class lever

Answer 7

Effort and fulcrum either side of the of the load in the middle

E - L - F

Question 8

Example of second class levers

Answer 8

Ball of the foot in the take off phase of a high jump

Question 9

Third class lever

Answer 9

Load and fulcrum either side of the effort in the middle

L - E - F

Question 10

Effort arm

Answer 10

The distance from the fulcrum to the effort

Question 11

Load arm

Answer 11

The distance from the load to the fulcrum

Question 12

Mechanical advantage

Answer 12

Second class lever systems where the effort arm is greater than the load arm.

A large load can be moved with relatively small effort.

Question 13

Mechanical disadvantage

Answer 13

Third class lever systems where the load arm is greater than the effort arm.

A large effort is required to move a relatively small load