Test 3

Question 1

a body will remain at rest or continue to move with a constant speed in a straight line unless acted upon by an outside force

Answer 1

Newtons 1st law

Question 2

Law of acceleration

F=ma

Answer 2

Newtons 2nd law

Question 3

a force that is causing a body to speed up

force is in the same direction

Answer 3

propulsive force

Question 4

a force that is causing a body to slow down

force is in the opposite direction

Answer 4

braking force

Question 5

a force does not cause an acceleration, a _______ does.

Answer 5

net effective force

Question 6

for every force, there is an equal and opposite reaction force

Answer 6

Newtons 3rd law

Question 7

_____ opposes motion b/w two objects in contact and will always be ______ to the contact area

Answer 7

Friction

parallel

Question 8

what is the revised newtons 2nd law

Answer 8

F= mv/t

Question 9

formula for impuse

Answer 9

force x time

Question 10

______ is equal to change in momentum

Answer 10

Impulse

Question 11

what 3 things can you do to change your ability to rotate an wheel?

Answer 11

• increase length of lever arm
• apply force perpendicular to rigid body
• apply larger force by using foot or leg

Question 12

the turing effect of a force

Answer 12

Torque (T) or moment of force (M)

Question 13

formula for torque

Answer 13

T= moment arm x force

Question 14

distance from the axis of rotation to the point of force application

Answer 14

lever arm

Question 15

perpendicular distance from the force vector to the axis of rotation

Answer 15

moment arm

Question 16

formula for the angular equivalent of newtons 2nd law

Answer 16

T= moment of inertia x angular acceleration

Question 17

a torque that is increasing the speed of rotation

Answer 17

propulsive torque

Question 18

a torque that is decreasing the speed of rotation

Answer 18

braking torque

Question 19

a rigid body that is used in conjunction with a pivot point to multiply the force or speed applied to another body

Answer 19

lever

Question 20

what are the functions of a simple machine (lever)

Answer 20

1. balance 2 or more forces
2. change direction of the applied force
3. favor speed and ROM
4. favor force production

Question 21

FAR or RAF

Answer 21

1st class lever

Question 22

ARF OR FRA

Answer 22

2nd class lever

Question 23

AFR or RFA

Answer 23

3rd class lever

Question 24

lever that can do all four functions

Answer 24

1st class lever

Question 25

favors speed and ROM

Answer 25

3rd class lever

Question 26

favors force production

Answer 26

2nd class lever

Question 27

Resistance lever arm is always longer

Answer 27

3rd class lever

Question 28

force moment arm is always longer

Answer 28

2nd class

Question 29

examples of 1st class levers in body

Answer 29

neck extension | elbow extension

Question 30

examples of 2nd class levers in body

Answer 30

push up | toe raises

Question 31

examples of 3rd class levers

Answer 31

elbow flexion knee extend and flex shoulder extend and flex hip extend and flex

Question 32

most common type of lever in the body

Answer 32

3rd class

Question 33

two forces that are equal in magnitude, opposite in direction, and in the same plane produce pure rotation with no translation

Answer 33

force couple

Question 34

angular impulse formula

Answer 34

impulse = torque x time

Question 35

angular impulse is equal to ______

Answer 35

angular momentum (H)

Question 36

To improve performance, we would want to ____________

Answer 36

maximize angular velocity

Question 37

to minimize injury risk, we would want to __________

Answer 37

decrease average torque

Question 38

a resistance that increases with the amount of force or torque applied

Answer 38

accommodating resistance

Question 39

Isokinetic dynamometers maintains constant _______ no matter the torque

Answer 39

angular velocity

Question 40

a special case where both the linear and angular accelerations are zero, and thus the sum of the external forces and sum of the external torques are zero

Answer 40

static equilibrium

Question 41

regardless of stance, the ______ cannot be located outside the _______ to maintain balance

Answer 41

COP | BOS

Question 42

the state of matter that makes things change, or has the potential to make things change

Answer 42

energy

Question 43

the energy that a body has due to its motion

Answer 43

kinetic energy

Question 44

the energy a body has that has the potential to change something but is not currently changing anything

Answer 44

potential energy

Question 45

formula for kinetic energy

Answer 45

KE= 1/2 mv squared

Question 46

the potential energy that a body has due to its position

Answer 46

gravitational potential energy

Question 47

the energy a body has due to its deformatin

Answer 47

strain potential energy

Question 48

the process of changing the amount of energy in a system

Answer 48

work

Question 49

formula for work

Answer 49

w= F x d

Question 50

_____ work means that the energy is entering the system

Answer 50

postive

Question 51

______ work means that the energy is leaving the system

Answer 51

negative

Question 52

to jump high you need to _____ your legs as much as possible at take off to increase ______ and increase _____

Answer 52

extend change in position potential energy

Question 53

at the top of a jump (apex), ________ = 0

Answer 53

kinetic energy

Question 54

as you go down, ______ energy is changed to ______ energy

Answer 54

potential energy is changed to kinetic energy

Question 55

the amount of mechanical energy that can be expended with a given amount of energy

Answer 55

efficiency

Question 56

the amount of energy required to perform a certain amount of work (MEE)

Answer 56

economy

Question 57

lower energy requirement for the same amount of work =

Answer 57

more economical movement

Question 58

- the time rate of doing work - how energy is leaving the system - how much force can be produced while moving quickly

Answer 58

power

Question 59

formula for power

Answer 59

power= work/ time (W)

Question 60

a collision where two objects bounce off each other without deformation or loss of heat

Answer 60

elastic collision

Question 61

examples of elastic collisions

Answer 61

colliding pennies, billiard balls

Question 62

a collision in which two objects stick together after they collide

Answer 62

inelastic collision

Question 63

example of inelastic collisions

Answer 63

football players colliding

Question 64

kinetic energy is conserved in a _______ collision

Answer 64

elastic

Question 65

Kinetic energy is not conserved in a ________ collision

Answer 65

inelastic

Question 66

the measure of elasticity of a collision between two objects

Answer 66

the coefficient of restitution (e)

Question 67

perfectly elastic collision

Answer 67

e= 1

Question 68

perfectly inelastic collision

Answer 68

e= 0

Question 69

the portion of a body's mass that is involved with a collision

Answer 69

effective mass