Standards/Plan

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Standards/Plan
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Standards
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Standards
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Standards
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Processes
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Standards
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Standards
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WARM UP
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Simple Harmonic Motion (SHM)

• 1)

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Simple Harmonic Motion (SHM)

• 1)

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Warm Up

• 2) A block is pushed along a horizontal,
  frictionless surface, with a horizontal Force
  that varies as a function of time as shown in the
  graph here. The mass of the bloc is 3kg. If the
  block was at rest at time t0, what is the speed
  of the block at time t3?

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Warm up 2
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Warm Up

• 3) Three blocks of mass m, 2m, and 3m are placed
  adjacent to each other on a frictionless
  horizontal surface as shown above. A constant
  force of magnitude F is applied to the right.
  Which of the following statements is true?

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Warm Up
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Warm Up

• 4) Two masses, Mgtm, are connected by a light
  string hanging over a pulley of negligible mass.
  When the masses are released from rest, the
  magnitude of the acceleration of the masses is?

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Warm Up

• 5) A mass of 2.0kg is attached to the end of a
  light cord to make a pendulum 5.0m in length. The
  mass is raised to an angle of 53 relative to the
  vertical, as shown, and released. The speed of
  the mass at the bottom of the swing is

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Warm Up

• 6) A cannon is mounted on a cart, and carrying a
  cannonball. The total mass of the cart, cannon,
  and ball is M, and the cart is rolling with no
  friction at a velocity v in the positive
  direction as shown above. The ball, of mass m, is
  fired with a velocity vball in the positive x
  direction. What is the velocity of the cart and
  cannon after the ball is fired?

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Warm Up

• 6)

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Warm Up

• Awesome Gas Video
• NO WARM UP!

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Warm Up

• 7) A student lies on a rigid platform of
  negligible mass, which is in turn placed upon two
  spring scales as shown above. The left scale at
  position 0 reads 200N, and the scale on the right
  at position L, reads 300N. Find the value of X in
  terms of L.
• a. X 1/2 L
• b. X 2/5 L
• c. X 3/5 L
• d. X 3/4 L
• e. X 4/5 L

PIVOT POINT
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Warm Up

• 8)

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Warm Up

• 8)

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Warm Up

• 9) A pendulum driven clock, located on earth, is
  set into motion by releasing its 10m long simple
  pendulum from a maximum angle of less than 10
  relative to the vertical. At what approximate
  time t will the pendulum have fallen to a
  perfectly vertical orientation? (Use 10 for g)

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Warm Up
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Warm Up

• 10) By visual inspection, order the PV diagrams
  shown from the most negative work done on the
  system to the most positive work done on the
  system.
• a,b,c,d
• a,c,b,d
• d,b,c,a
• d,a,c,b

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Lesson
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Announcements
Pass Back Fluids Quiz Thermo Quiz Friday!
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What are important quantities in thermodynamics?

• Pressure ? Atoms colliding w/ wall of a
  container
• Temperature ? How fast atoms move
• Volume ? How much space atoms need to move
  freely
• Number of molecules ?Really big numbers

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Kinetic Theory of Gases Assumptions for an IDEAL
GAS

• 1) Atom are bouncy
• Elastic collisions between atoms
• 2) Atoms are spread out
• Far away unless colliding
• 3) Atoms are random
• No preferred direction of motion (means pressure
  is equal everywhere in a container

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Calculation Units to use

• Pressure ? ALWAYS Pascals (N/m2 )
• Temperature ? ALWAYS Kelvin (273 oC)
• Volume ? ALWAYS m3 (Liters/1000)
• Number of molecules ?moles or molecules
• Moles Molecules/6.02E23
• R 8.31J/molK
• Kb 1.38 E-23 J/K

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Equations so far

• PV nRT
• PV NkbT
• P1 V1 / T1 P2 V2 / T2
• ?M is molar mass

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Energy of a Gas

• ?U Q W
• U 3/2 nRT
• U 3/2 PV

Energy Type () (-)
U Internal energy Temp INCREASE TEMP DECREASE
Q HEAT HEAD ADDED HEAT REMOVED
W Work GAS CONTRACTS (WORK ON) GAS EXPANDS (WORK BY)
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Gas Process

• The thermodynamic state of a gas is defined by
  pressure, volume, and temperature.
• A gas process describes how gas gets from one
  state to another state.

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Isothermal Process(constant temperature)
Hayon Pull plunger up from halfway (slowly)
T1
DT 0 (constant T)
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Isobaric Process(constant pressure)
Hayon Heat up the tank while allowing plunger to
move
DP 0 (constant P)
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Isometric Process(constant volume)
Hayon Push to the top and then heat up or push
to the bottom and then cool down
NO WORK POSSIBLE!!
DV 0 (constant V)
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Adiabatic process(PERFECTLY insulated)
NO HEAT IS TRANSFERED
?U W
Q 0 (no heat enters or leaves)
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Example Problem
0.25 moles of a gas are kept at 1150K. The gas
undergoes adiabatic expansion, reaching a final
temperature of 400K. How much work was done on or
by the gas? U 3/2 nRT
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Using PV Diagrams
Hayon Test (remember area) and dont use 1 way
valve
WORK Area under a PV Diagram
() Contract (-) Expand
200kpa
100kpa
300m2
250m2
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Free Response Problems

• FR 1 as an Example
• Web Assign Thermo Assignment 2
• Then skip 2 and go to the back