chapter 4

Question 1

work

Answer 1

the product of force applied to a body and the amount of displacement the body undergoes

Question 2

work letter

Answer 2

U

Question 3

does work need time

Answer 3

no

Question 4

work unit

Answer 4

Nm or J

Question 5

to calculate work we need

Answer 5

force, displacement

Question 6

concentric

Answer 6

against gravity

Question 7

eccentric

Answer 7

with gravity

Question 8

positive mechanical work is done by

Answer 8

force acting on an object if the object displaces in the same direction of the force
concentric

Question 9

negative mechanical work is done by

Answer 9

force acting on the object when the object displaces in the opposite direction of the force acting on it
eccentric

Question 10

positive muscle work

Answer 10

a muscle contracts and its point of attachment move in the direction of the muscle pull
concentric contraction

Question 11

negative muscle work

Answer 11

a muscle contracts and its points of attachment move in the direction opposite the muscle pull
eccentric contraction

Question 12

does an isometric contraction perform mechanical work

Answer 12

no

Question 13

energy

Answer 13

the capacity to do work

Question 14

two types of mechanical energy

Answer 14

kinetic, potential

Question 15

kinetic vs potential energy

Answer 15

kinetic is motion, potential is stored

Question 16

two types of potential energy

Answer 16

postion, deformation

Question 17

an objects capacity to do work because of its

Answer 17

motion

Question 18

how much KE in a 5oz baseball (145g) thrown at 80mph (35.8m/s)

Answer 18

KE=.5mv^2=92.9J

Question 19

gravitational PE

Answer 19

energy inherent due to an objects position relative to the earth (vertical energy)

Question 20

strain PE

Answer 20

energy stored due to an objects deformation

Question 21

gravitational evergy formula

Answer 21

PE=mgh

Question 22

calculate strain energy stored in a tendon stretched 5mm if the stiffness (k) of the tendon is 10,000 N/m

Answer 22

SE=.5k (triangle x)^2
.125J

Question 23

work energy principle:
the net work done by all the external forces acting on an object causes a change in the

Answer 23

mechanical energy of the object

Question 24

as a moving object rises up in the air
KE ____
PE____
total energy ____

Answer 24

decrease, increase, constant

Question 25

as a falling object gets closer to the ground
KE ____
PE_____
total energy____

Answer 25

increase, decrease, constant

Question 26

power

Answer 26

rate of doing work

Question 27

cyclical activities

Answer 27

walk, run, cycle, swimming

Question 28

cadence

Answer 28

rate of running or walking

Question 29

velocity of locomotion

Answer 29

cycle rate x cycle length

Question 30

cycle rate

Answer 30

how often the motion is repeated per minute

Question 31

cycle length

Answer 31

what distance is traveled per cycle

Question 32

to move faster or slower, performer can change

Answer 32

cycle rate, length or both

Question 33

power output and endurance are ____ related

Answer 33

inversely

Question 34

high power output sustainable for

Answer 34

shorter duration

Question 35

low power output sustainable for

Answer 35

longer duration