# Basic Mechanical Principles Flashcards Preview

## Biomechanics Exam 1 > Basic Mechanical Principles > Flashcards

Flashcards in Basic Mechanical Principles Deck (17)
1
Q

What is a force?

A
• An action of one body acting on another
• A push or pull on a system
2
Q

What are forces characterized by?

A
• Magnitude (lbs)
• Location
• Direction
• Duration
• Frequency
• Rate
3
Q

What are common forces that act upon the human body? What is each?

A
• Gravity: pull of Earth of an object; the “weight”
• Externally applied resistance: outside forces acting on the body; weight or people
• Friction: resistance to movement
• Muscles: internal force that inhibits torque and rotation of joints
4
Q

What are force vectors? What factors do they represent?

A
• Arrows that represent forces
• Magnitude (length of arrow)
• Direction
• Point of application
• Line of application
5
Q

What is a free body diagram? What does it show?

A
• A pictorial representation of all forces of an object
• When you line them up end to end, it shows how the forces added together will move the object (if at all)
6
Q

What is Newton’s 1st Law?

A

-* “Law of inertia”
- Objects in motion remain in the same motion until acted upon by an outside force
- Objects at rest remain at rest until acted on by an outside force

7
Q

What is Newton’s 2nd Law?

A

“Law of acceleration”
- An object will accelerate in the direction of the force applied to it
- Magnitude of acceleration will be proportional to the force applied and inversely proportional to its mass

8
Q

What is Newton’s 3rd Law?

A

Law of action and reaction”
- Every action has an equal and opposite reaction

9
Q

What are the six parts of a lever? What is each? What is an example of the human body for each?

A
• Axis / fulcrum = pivot point (joint)
• Lever = rigid bar (bones)
• Resistance (load) force = force trying to overcome (weight)
• Resistance arm = lever from resistance to fulcrum
• Effort (moving) force = force against resistance (muscles)
• Force (effort) arm = lever from effort to fulcrum
10
Q

What is a first class lever? What is an example from the body?

A
• Axis / fulcrum lies in between the 2 forces
• Triceps extension
11
Q

What is a second class lever? What is an example from the body?

A
• RESISTANCE / LOAD is in the middle of the effort and fulcrum
• Calf raise
12
Q

What is a third class lever? What is an example from the body?

A
• EFFORT is in the middle of the fulcrum and load
• Almost every action in the body
13
Q

How do can I remember which class lever is which?

A
• The acronym: FREe
• F = first letter = first class = fulcrum in the middle
• R = second letter = second class = resistance in the middle
• E = third letter = third class = effort in the middle
14
Q

“Effort creates the force, which creates movement.”

A

Indeed it does

15
Q

When talking about body weight as being resistance, where does the resistance come from?

A

The center of mass of the body or objec

16
Q

T/F: The fulcrum can move in levers.

A
• False
• The fulcrum doesn’t move and stays fixed
17
Q

What is considered the effort point for many of the body’s movements?

A
• Where the muscle inserts into the lever (bone)
• Remember the body is mostly 3rd class levers