Energy Test Flashcards
The scalar product between two vectors
A • B = A • B • cosø
What is work?
W = F • ∆d = F d cosø
total work is = Fnet
Conservative forces
- FA
- FK
- FR
Kinetic vs Potential energy
Kinetic energy; Eg = mgh
Potential energy; Ek = 1/2 mv2
Mechanical Energy (E)
E = Eg + Ek
E = mgh + 1/2mv2
isolated system
A system that does not experience:
- applied force
- friction
- air resistance (drag)
E = EK + EG = constant
∆E = 0
non-isolated system
A system that DOES experience:
- FA
- FK
- FR
∆E = W (work)
equal to J?
[E] = [Ek] = [Eg] = [W] = 1J
If Eg is constant
(non-isolated)
∆EK = W
( ∆EK + ∆Eg = W )
( ∆EK + 0 = W )
( ∆EK = W )
If Ek is constant
(non-isolated)
∆Eg = W
( ∆Eg + ∆EK = W )
( ∆Eg + 0 = W )
( ∆Eg = W )
Power equation
P = ∆E / ∆t
or
(P =) J / s = W (att)
(power is a watt)
Thermal energy
[TE] = J
Kinetic Molecular Theory
- matter is made up of particles
- particles attract (N4)
- particles are in constant motion
Thermal Energy is the total of what
kinetic energy + potential energy
Temperature scales
- celsius
- fahrenheit
- kelvin (TC +273.15)
0k is absolute zero
Heat
heat is the change in T.E.
[Q] = 1J
Specific Heat Capacity
Cw = J / kg • ˚C
Heat equation
Q = mc ∆T
Q = mc (T2 - T1)
Isolated heat system
Qabsorbed + Qreleased = 0
1 Watt
the power of energy transformation that converts 1J of energy into another form, in one second.
1 Joule
the work done by 1N of force that produces a displacement of 1m
Specific heat capacity def.
the amount of heat absorbed that is required for 1kg of a substance to increase its temperature by 1 ˚C
(J / kg • ˚C)
