ENERGY WORK POWER

Question 1

energy

Answer 1

the ability to do work

Question 2

energy is a scalar or vector

Answer 2

scalar

Question 3

translational kinetic energy

Answer 3

capacity to do work by virtue of a body’s linear motion

Question 4

rotational kinetic energy

Answer 4

capacity to do work by virtue of a body’s rotational motion

Question 5

gravitational potential energy

Answer 5

capacity to do work by virtue of a body’s position

Question 6

describe gravity in gravitational potential energy formula

Answer 6

gravity will be input as positive because you can’t have negative energy

Question 7

can you have negative energy

Answer 7

NO

Question 8

strain/spring potential energy

Answer 8

capacity to do work by virtue of a deformed body returning to its original shape

Question 9

what is k in the strain/spring potential energy formula

Answer 9

spring constant
-the stiffness of the spring

Question 10

describe example of strain/spring potential energy

Answer 10

an eccentric movement like a golf swing that stretches the tissues (stores potential energy in the tissue itself)
-benefit from the concentric of the movement

Question 11

heat energy

Answer 11

energy lost is dissipated as heat
-micro-movement of particles

Question 12

work

Answer 12

change in mechanical energy

Question 13

mechanical energy

Answer 13

kinetic + potential energy

Question 14

if movement is in the opposite direction as the force applied then work will be positive/negative
-what type of movement
-what occurs
-name an example of this for a push up

Answer 14

negative
-eccentric movement
-attempting to decelerate the body absorbing kinetic energy
-down phase of push up

Question 15

if movement is in the same direction as the force applied then work will be positive/negative
-what type of movement
-what occurs
-name an example of this for a push up

Answer 15

positive
-concentric movement
-attempting to accelerate the body generating kinetic energy
-up phase of push up

Question 16

if no movement occurs, with applied force, describe mechanical work
-what type of movement
-name an example of this in exercise

Answer 16

mechanical work = 0
-isometric movement
-isometric plank

Question 17

ergometry

Answer 17

quantifying work performed by the body
-change in energy

Question 18

conservative force

Answer 18

a force where work done by that force in moving an object from starting point A to end point B is independent of the path the object takes

Question 19

example of a conservative force

Answer 19

gravity
-work done by gravity is not path dependent

Question 20

name a non-conservative force

Answer 20

friction

Question 21

does conservative force mean positive work

Answer 21

NO
-just because a force has done negative work doesn’t mean that the force was not a conservative force
-spring forces + gravitational forces store potential energy as they perform negative work on an object

Question 22

conservation of mechanical energy

Answer 22

when all forces acting on a body are conservative the body’s total mechanical energy remains constant (projectile motion)

Question 23

can COM be outside physical body

Answer 23

yes

Question 24

Fosbury flop

Answer 24

passing body over bar causes COM to pass under bar

Question 25

ergometer

Answer 25

work-measuring device
-measures torque over a certain displacement

Question 26

point mass method

Answer 26

work as a change in total energy of the COM
-estimate a body as behaving as just a single COM + quantify changes in energy by changes in the gravitational + translational kinetic energy of the body

Question 27

what doesn’t the point mass method account for

Answer 27

rotational kinetic energy

Question 28

what is point mass method termed

Answer 28

zero work paradox

Question 29

zero work paradox (for point mass method)

Answer 29

even though you may be putting a lot of effort into a movement, depending on what that movement is, it may not show up in the point mass method

-EX: walking
-1 cycle of walking- heel strike on right side through gait cycle back to heel strike on right side
-point pass method would estimate 0 work done; limited for calculating work of a body when you get back to the same point

Question 30

what does mechanical efficiency in biomechanics take into account

Answer 30

physiological cost
-uses gas exchange to figure out metabolic cost for things like a walk

Question 31

power

Answer 31

the rate at which work is performed
-rate of energy generation or dissipation

Question 32

what is the integral of power (area underneath the power curve)

Answer 32

work

Question 33

work is the are under what curve

Answer 33

joint power curve

Question 34

above 0 on joint power curve = ?

Answer 34

positive work
-concentric muscle conctraction

Question 35

below 0 on joint power curve = ?

Answer 35

negative work
-eccentric muscle contraction