Mechanical Principles Test 1 Flashcards
Weight
Earths gravitational pull.
Relative to the center of the earth
Force
Mass
Contains substance or matter
What is the correlation between mass and weight?
They are perfectly correlated. As one doubles, so does the other
Newtons first law of motion
Law of inertia.
A body at rest will stay at rest or continue at a constant velocity and in a straight line unless acted upon by an external unbalanced force
Inertia
Resistance to change
What is the correlation between inertia and mass?
It is directly related to mass. more mass= more resistance to change
Equation for speed
And def.
D/t
Distance/time
How fast an object is traveling
Scalar quantity measures what?
Only measures magnitude
Acceleration/deceleration def. and equation
A=F/M
OR
A= change of velocity/ change of time
Rate that speed changes
Velocity equation
V=s/t
Vector quantity
Measures magnitude and direction
Velocity
Force equation
Force= mass X acceleration
Newtons second law of motion
Law of acceleration.
Acceleration of an object is directly proportional to the force acting on it, is in the same direction of the force acting on it, and is inversely related to the mass of the object
Center of gravity
The point at which weight is evenly distributed over a center point.
Point at which mass and weight are balance in every direction.
Point where gravitational forces are centralized
Newtons third law of motion
Reaction force.
For every action there is an equal and opposite reaction
Equation for impulse and definition
Impulse= force X time
OR
Impulse= mv final - mv initial
Force applied to an object over time
Change in momentum
Force definition
A push or pull that changes the state or motion of an athlete or object.
External and internal forces
External forces
Gravity, ground reactive forces, friction, areas distance, contact forces from opposing athletes
Internal forces
Muscles
Projectile definition
Something or someone traveling through the area that will eventually hit the ground.
Trajectory- horizontal + vertical direction
What three factors influence the projectile
Angle of release
speed of release
Height of release
Angle of release:
What Does it determine? And the three types of releases
Determines shape of flight path. Straight vertical, above 45° – height>distance
Below 45- distance > height
45- distance=height
Straight vertical
Speed of release
what does it determine, and how does it work
Determine size of flight path
Increasing speed increases apex and distance
What is an Apex?
Highest point of flight path
A
O
I
Sternocleidomastoid muscle
A: neck flexion
O: manubrium and clavicle
I: mastoid process
Rectus Abdominis muscle
AOI
A: back flexion, posterior pelvic flexion
O: pubic crest, pubic symphysis
I: costal cartilage of ribs 5-7, xiphoid process
External oblique abdominal muscle
AOI
A: back flexion, posterior pelvic rotation
O: lower borders of ribs 5-12
I: anterior half of the iliac crest, pubic symphysis, superior margin of pubis
Internal oblique abdominal muscle
AOI
A: lumbar flexion, posterior pelvic rotation
O: Inguinal ligament, iliac crest, thoracolumbar fascia
I: costal cartilage of ribs 8-10, ribs 10-12, linea alba
Transverse Abdominis muscle
AOI
A: compression of abdominal cavity
O: inner surface of ribs 7-12, inner surface of iliac crest, Inguinal ligament
I: linea alba, pubis aponeurosis of internal oblique
Equation for momentum
Momentum= mass X velocity
Mechanical work equation
Work= force X distance
Power equation
Power= force X distance/ time
OR
Power= work/ time
Strength definition
Amount of force produced in a single effort
Kinetic energy definition and equation
KE= 1/2mv^2
Energy in action
Potential energy equation and definition
PE= mgh
Stored energy ready for use. When it’s put into use, it’s kinetic
Correlation between height and kinetic energy
As height increasing so does kinetic energy
Strain energy
Stored energy in obstacles that are strained but can be restored to their original shape
Rubber band
Static friction def. and equation
Between the surface of two objects in contact with each other.
Is the resistive force for the initiation of movement
F=mn
Sliding friction
A type of kinetic friction.
Resistive force between the surfaces to you sliding object
Rolling friction
Type of kinetic friction. Resistive force of the surface of one object rolling over the surface of another object.
What is rolling friction affected by
Fiction between the two surfaces in contacts. Pressure or weight between the two surfaces
Diameter of the rolling object
What is the order of the frictions
Static> sliding> rolling
