Work and Energy

Question 1

energy

Answer 1

referes to a system’s ability to do work

Question 2

kinetic energy

Answer 2

objects that have mass and are moving

Question 3

kinetic energy formula

Answer 3

K=(1/2)mv^2

Question 4

Joule

Answer 4

measurement of energy; kg*m/s^2

Question 5

potential energy

Answer 5

energy associated with a given object’s position in space; has the potential to do work

Question 6

gravitational potential energy

Answer 6

depends on an object’s position with respect to some level identified as the datum (ground, or 0 PE)

Question 7

gravitational potential energy equation

Answer 7

U=mgh

Question 8

elastic potential energy

Answer 8

U=1/2kx^2, where x is the magnitude of displacement from equilibrium and k is the spring constant

Question 9

total mechanical energy

Answer 9

sum of an object’s U and KE; E=U+K

Question 10

first law of thermodynamics

Answer 10

conservation of mechanical energy; energy is never created nor destroyed

Question 11

conservative forces

Answer 11

path independent and do not dissipate energy; i.e. gravitational and electrostatic; all energy is conserved

Question 12

nonconservative forces

Answer 12

friction, air resistance, viscous drag; total mechanical energy is not conserved

Question 13

work

Answer 13

process by which energy is transferred from one system to another

Question 14

Work equation

Answer 14

W=Fdcos(theta)

Question 15

P-V graphs

Answer 15

shoe the work done on or by a system undergoing a thermodynamic process

Question 16

isovolumetric (isochoric) process

Answer 16

volume stays the same and no work is done

Question 17

isobaric process

Answer 17

volume changes, pressure stays the same; W=P(delta)V

Question 18

P-V graph calculation

Answer 18

calculate area of all regions then add together to find work

Question 19

Power

Answer 19

rate at which energy is transferred from one system to another P=ΔE/t

Question 20

Watt (W)

Answer 20

Joules/sec

Question 21

work-energy theorem

Answer 21

Wnet=ΔK=Kf-Ki

Question 22

simple machines

Answer 22

inclined plane, wedge, wheel and axle, lever, pulley and screw

Question 23

mechanical advantage

Answer 23

ratio of the force exerted on an object by a simple machine (Fout) to the force actually applied on the simple machine (Fin) (Fout/Fin)

Question 24

load distance v effort distance

Answer 24

in order to lift an object a certain load distance, the length of rope must be twice that distance

Question 25

efficiency of a simple machine

Answer 25

Wout/Win aka loadload distance/efforteffort distance