As the surface area of two objects in contact increases, what happens to the force of friction?

remains constant

The force that acts parallel to an object in contact with a surface is called-

friction force

The force that acts perpendicular to an object in contact with a surface is called-

normal contact force

As the normal contact force increases, what happens to the friction force?

increases

push or a pull

forces

When drawn, the length of a vector describes it-

magnitude

A free-body diagram displays:

forces acting on a body

Concurrent forces are forces that-

act through same point

To fully define a vector quantity, you must specify-

direction

magnitude

magnitude

the process of determining each of the forces that combine to make up a resultant force is called-

force resolution

units of accelerations are-

m/s^2

what factor differentiates velocity from speed?

direction

velocity is calculated as-

displacement/time

what term best describes linear motion along a curved line?

curvilinear

acceleration describes the time rate of change of-

velocity

elbow extension takes place in what plane?

sagittal

abduction occurs in which plane?

frontal

the cardinal frontal plane divides the body into equal _____

front and back halves

movements in transverse plane occur around which axis?

longitudinal

Examples of sagittal plane movement-

flexion

extension

plantar flexion

extension

plantar flexion

description used when one of intersecting lines in immovable relative to the earth

absolute angular position

description used when both intersecting lines are capable of moving

relative angular position

considered the starting point for all body segment movements (starting point of motion)

anatomical position

divides body vertical into left and right halves

ex- running, summersalt

ex- running, summersalt

sagittal plane

divides body into front and back halves

ex- jumping jacks

ex- jumping jacks

frontal plane

divides body into top and bottom halves

ex- spins, pirouette

ex- spins, pirouette

transverse plane

imaginary line passing through body from side to side

transverse axis

sagittal plane rotation occurs

transverse axis

passing from front to back through body

anteriorposterior axis

frontal plane rotation occurs

anteriorposterior axis

passes from top to bottom

longitudinal axis

transverse plane rotation occurs

longitudinal axis

each axis is associated with the plane it is __________ with

perpendicular

orientation of a line with another line

angular position

change in absolute angular position experienced by a rotating line

angular displacement

force that is exerted by one object on another ________

action

force is matched by an equal but opposite force exerted by the second object _______

reaction

units of force

Newton N

internal forces

tensile

compression

compression

-internal force that pulls

-ligaments are stretched

-rubber band

-ligaments are stretched

-rubber band

tensile

-internal force

-pushing force action on the end

-sponge. (ex- spinal compression)

-pushing force action on the end

-sponge. (ex- spinal compression)

compression

contact forces always come in pairs _____ & ________

action

reaction

reaction

gravitational acceleration

9.81 m/s^2

weight (N)

mass * gravity

example of contact force

shot putter

jumping

jumping

parallel to surface in contact

friction

interaction between molecules of the surface in contact

dry friction

friction that acts between two surfaces that are not moving relative to one another

static friction

what is proportional to normal contact force

frictional force

what acts perpendicular to the normal contact force and parallel to the surface

frictional force

________ is affected by material type in contact with the surface

frictional force

mathematical description of static friction force-

(F)= mu*R

In friction equation (F)= mu*R

what does R stand for?

what does R stand for?

normal contact force

mathematical representation of any quantity defined by size/magnitude and direction/orientation

vector

length of vector =

magnitude

vectors line of application =

orientation

direction of vector =

arrowhead

determining a single vector from two or more vectors by vector addition

vector composition

replaces a single vector with two perpendicular vectors

vector resolution

if vectors are same direction you _______ magnitudes

add

if vectors are in opposite direction you_________ magnitudes

subtract

-this is the sketch of system and all external forces acting on it

-representation of all external forces and moments acting on the system of interest

-representation of all external forces and moments acting on the system of interest

free body diagram

an object is in ________ equilibrium if all forces are balanced

static

-person isn’t accelerating

-person ins’t moving, the sum of all forces acting on them must be 0

-person ins’t moving, the sum of all forces acting on them must be 0

static equilibrium

where something is located in space

-1 dimensional, 2 dimensional

-1 dimensional, 2 dimensional

position

length of the path followed by the object from initial to final position

-direction is not important

-direction is not important

distance travelled

-direction of movement is taken into account

-straight line distance from initial to final position

-vector quantity

-straight line distance from initial to final position

-vector quantity

average displacement

distance travelled divided by the time it took to travel that distance

average speed

=distance travelled/total duration

-nothing about direction

average speed (m/s)

displacement of an object divided by time it took for that displacement

average velocity

=displacement/total duration

average velocity (m/s)

________ is the rate of motion

speed

is the rate of motion in specific direction (rate of displacement)

-vector quantity

-vector quantity

velocity

these are the same if motion is in a straight line with no change in direction

ex- sprint, walking, swimming

ex- sprint, walking, swimming

speed

velocity

velocity

measured over an instant of time rather than a total duration of time

instantaneous speed and velocity

rate of change of velocity

average acceleration

=change in velocity/total duration

average acceleration (m/s^2)

object ___________ if magnitude of velocity is changing

accelerates

ex= “5 meters per second east”

(if change in speed, direction, or both)

(if change in speed, direction, or both)

velocity

ex= how *fast a car is being driven, how *quick a jaguar runs

speed

you are ________ when you change speed or direction

ex= car speeding up after stopping at a red light

ex= car speeding up after stopping at a red light

accelerating

in anatomical position, the forearm is in what position?

supinated

Which of the following limb movements dominate during jumping jacks?

adduction

abduction

abduction

Movement of the hand at the wrist toward the ulnar side of the arm is-

ulnar deviation

What term is used to describe the motion of bringing the toes closer to the lower leg?

dorsiflexion

The movement to increase the angle between the thigh and lower leg is defined as-

knee extension