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Chapter 2, Section 8. Potential and Kinetic Energy: Energy in the Pole Vault. November 1, 2010 HW: 2.8 PTG #1, 2, 3, 6, 7, 8, 13, Due Friday. Learning Objectives: Describe kinetic, gravitational potential, and elastic energy and the variables that influence them - PowerPoint PPT Presentation
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Chapter 2, Section 8
Potential and Kinetic Energy: Energy in the Pole Vault
November 1, 2010HW: 2.8 PTG #1, 2, 3, 6, 7, 8, 13, Due Friday• Learning Objectives:
Describe kinetic, gravitational potential, and elastic energy and the variables that influence them
– Explain conservation of energy
• Success Criteria:– Apply equations for kinetic energy,
gravitational potential energy, and elastic energy
– Recognize that restoring forces are active when objects are deformed
– Apply the equation for the force necessary to compress or stretch a string
– Conduct simulations of transformations of energy involved in the pole vault.
• Do Now: – Write LO and SC in
notebook– WDYS/WDYT
• pg 220
• Agenda:– Do Now– LO/SC– Investigate
Investigate #1-9• Worksheet from
Mattea
November 2, 2010HW: 2.8 PTG #1, 2, 3, 6, 7, 8, 13, Due Friday• Learning Objectives:
Describe kinetic, gravitational potential, and elastic energy and the variables that influence them
– Explain conservation of energy
• Success Criteria:– Apply equations for kinetic energy,
gravitational potential energy, and elastic energy
– Recognize that restoring forces are active when objects are deformed
– Apply the equation for the force necessary to compress or stretch a string
– Conduct simulations of transformations of energy involved in the pole vault.
• Do Now: – Thinking about pole
vaulting…• What did the ruler
represent?• The ball?• The penny?
• Agenda:– Do Now– LO/SC– Investigate(Finish)– Physics Talk
2.8 Physics Talk• What is happening
to speed at each position?
1. Force gives the ball an upward speed
2. Speed decreases as the ball is acted upon by gravity
3. Vertical position is maximum, but vertical speed is 0
4. Ball increases in speed as it is acted upon by gravity
1
4
3
2
2.8 Physics Talk• What changed in
terms of energy?• Total energy is
always the same, it is just transformed from one form to another
2.8 Physics Talk• What is Kinetic
Energy (KE)?
• What is Gravitational Potential Energy (GPE)?
• Energy associated with motion
• The energy an object possesses because of its vertical position from Earth
2.8 Physics Talk• What is potential
energy (PE)?
• What is the Law of Conservation of Energy?
• Energy associated with position (stored)
• Energy cannot be created or destroyed! It can be transformed from one form to another but the total energy remains constant!
2.8 Physics Talk• What changed in
terms of energy?1. Ball has only
kinetic energy
2. Kinetic energy decreases, Gravitational Potential Energy increases
3. Kinetic Energy=0, Max GPE
4. GPE decreases, Kinetic Energy increases1
4
3
2
2.8 Physics Talk• What energy is
needed to get the ball moving? To get it to stop?
• What is the equation for Work?
• WORK!• Work is the force
applied over a distance
• Causes the change in forms of energy
• Work=Force x Distance• W=Fd• Units=Joules J
W
dF
Think about launching the penny…• Work was done on the ruler to add energy to
the system• After bending the ruler it had Elastic Potential
Energy• When you released the ruler it applied a force
over a distance to the penny (work)• The penny now has Kinetic Energy• As it travelled up, the KE became GPE• At the peak, the penny had no KE and all GPE• As the coin fell GPE became KE• Sum of the GPE and KE was always the same
(conservation of energy)
November 3, 2010HW: 2.8 PTG #1, 2, 3, 6, 7, 8, 13, Due Friday• Learning Objectives:
Describe kinetic, gravitational potential, and elastic energy and the variables that influence them
– Explain conservation of energy
• Success Criteria:– Apply equations for kinetic energy,
gravitational potential energy, and elastic energy
– Recognize that restoring forces are active when objects are deformed
– Apply the equation for the force necessary to compress or stretch a string
– Conduct simulations of transformations of energy involved in the pole vault.
• Do Now: – Explain what
happens to KE and PE as you ride your bike up a hill.
• Agenda:– Do Now– LO/SC– Vocab Activity
Pole Vaulting!!!• http://www.youtube.com/watch?v=kJu
citWzywM&feature=fvw• Food energy provides muscular
energy to run which is KE• Vaulter’s KE is converted to Elastic PE
in the pole• As the pole unbends, EPE is
transferred to the vaulter as GPE• As vaulter falls GPE is transferred to
KE• Total energy remains the same!
Equations!!!• Work
• Elastic (spring)PE
• W=FdF=force (N)
d=distance (m)
W=work (Joules J)
• EPE=1/2kx2
K=spring constant (N/m)
x=amount of bend in meters
EPE=Joules (J)
Equations!!!• Gravitational
Potential Energy
• Kinetic Energy
• GPE=mghGPE=Joules (J)
m=mass (kg)
g=gravity (m/s2)
h-=height (m)
• KE=1/2mv2
KE=Joules (J)
m=mass (kg)
v=speed (m/s)
Practice Problems• Pg. 226-227• #1-Whole group• #2-Whole Group• #3-Small Group• #4-Individually
Vocab ActivityBook Definition Definition in your words
2.8 Vocab Boxes.docx
Example or Equation Picture/Drawing
November 4, 2010HW: 2.8 PTG #1, 2, 3, 6, 7, 8, 13, Due Friday• Learning Objectives:
Describe kinetic, gravitational potential, and elastic energy and the variables that influence them
– Explain conservation of energy
• Success Criteria:– Apply equations for kinetic energy,
gravitational potential energy, and elastic energy
– Recognize that restoring forces are active when objects are deformed
– Apply the equation for the force necessary to compress or stretch a string
– Conduct simulations of transformations of energy involved in the pole vault.
• Do Now: – Find the equations
for EPE, KE, W, etc.
• Agenda:– Do Now– LO/SC– Practice Problems
Practice Problems• W
ork and Energy Practice Problems.pdf
November 5, 2010HW: None
• Learning Objectives: Describe kinetic, gravitational
potential, and elastic energy and the variables that influence them
– Explain conservation of energy
• Success Criteria:– Apply equations for kinetic energy,
gravitational potential energy, and elastic energy
– Recognize that restoring forces are active when objects are deformed
– Apply the equation for the force necessary to compress or stretch a string
– Conduct simulations of transformations of energy involved in the pole vault.
• Do Now: – Get out 2.8 HW
• Agenda:– Do Now– LO/SC– Review HW– Relay!
Relay• Energy Relay.pdf• Work and Energy Relay.pdf