test2

Question 1

kinetics

Answer 1

the branch of dynamics concerned w the forces that cause or tend to cause motion

Question 2

law of inertia

Answer 2

every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that stage by the forces impresses upon it

Question 3

law of acceleration

Answer 3

(object will accelerate in direction of force) the change of motion of an object is proportional to the force impressed; and is made in the direction of a straight line in which the force is impressed

Question 4

law of action reaction

Answer 4

to every action, there is always am opposed and equal reaction: or the mutual action of two bodies upon each other are always equal and directed to contrary parts

Question 5

law of universal gravitation

Answer 5

all objects attract each other with a gravitational force that is inversely proportional to the square of the distance between objects

Question 6

what formula is associated with newton’s second law?

Answer 6

EF=ma

Question 7

impulse

Answer 7

the product of force and the time during which the force acts (change in momentum)

Question 8

momentum

Answer 8

the product of an objects mass and linear velocity

Question 9

relation between impulse and momentum

Answer 9

the impulse produced by the net force acting over some duration of time causes a change in momentum of the object upon which net force acts

Question 10

coefficient if restitution

Answer 10

the absolute value of the ratio of the velocity of separation to the velocity of approach

Question 11

the relationship between mass and weight

Answer 11

mass is how much matter an object has; weight is mass including the effects of gravity

Question 12

mechanical work

Answer 12

the product of force and the amount of displacement that occurs in the direction of that force (it is the means by which energy is transferred from one system to another)

Question 13

positive work

Answer 13

when they contract and their point(s) it attachment move in the direction of the muscle force pulling on them (force and displacement are in the same direction) muscle shortens, contraction is concentric

Question 14

negative work

Answer 14

when they contract and their pint(s) of attachment (force and displacement in opposite direction); muscle lengthens, contraction is eccentric

Question 15

in a concentric lift, what kind of work is done?

Answer 15

POSITIVE

Question 16

in an eccentric lift, what kind of work is done

Answer 16

NEGATIVE

Question 17

in an isometric lift, what kind of work is done?

Answer 17

no work is done; occurs when a muscle contracts and it’s points of attachment do not move relative to each other- displacement=0 at point of muscle attachment

Question 18

energy

Answer 18

the capacity to do work

Question 19

kinetic energy

Answer 19

energy due to motion

Question 20

gravitational potential energy

Answer 20

energy due to position relative to the earth

Question 21

strain energy

Answer 21

energy due to deformation of an object

Question 22

relationship between mechanical work and energy

Answer 22

work- means by which energy is transferred from one object to another; energy- capacity to do work

Question 23

power

Answer 23

the rate of doing work (how much work is done in a specific amount of time) how quickly or slowly

Question 24

centric force

Answer 24

change in linear motion; external force that is directed through the center of gravity of an object

Question 25

eccentric force

Answer 25

change in liberal and angular motion; external force that is not through the center of gravity

Question 26

torque

Answer 26

the turning (rotation) effects produced by a force- angular and rotary force

Question 27

counterclockwise torque

Answer 27

positive

Question 28

clockwise torque

Answer 28

negative

Question 29

force couple

Answer 29

a pair of external forces that cause change in only the angular motion of an object

Question 30

relationship of torque and weight training

Answer 30

muscles create the torques that turn our limbs and that pulls on its point of attachment to the skeletal system when it contracts

Question 31

torque in static equilibrium

Answer 31

the net torque acting on an object must sum to zero to ensure that no changes occur in the angular motion of an object, for an object to truly be in equilibrium, the external forces and external torque (about any axis) must sum to zero

Question 32

resultant of two or more torques

Answer 32

can add or subtract torques that act around the same axis, just like forces that act in the same direction- in planar situations, we can calculate the net torque by summing the torques that act on an object

Question 33

center of gravity

Answer 33

the point in a body or system around which it’s mass or weight is evenly distributed or balanced through which the force of gravity acts

Question 34

center of mass

Answer 34

the point in a body or system of body’s as which the entire mass may be assumed to be concentrated

Question 35

stability

Answer 35

the capacity of an object to return to equilibrium or its original position after being displaced (not easily moved or thrown off balance)

Question 36

where should COG be located to maximize stability

Answer 36

should be located within base of support

Question 37

what happens if the COM falls out of the base of support

Answer 37

the object will fall

Question 38

estimate the center of gravity on the body

Answer 38

approximately 2.5-5.0cm below your navel (slightly higher than half of your standing height (55-57%)