Download Day 4 * Spring, potential, kinetic energy

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Day 4 – Spring, potential, kinetic
energy
Mr. Lambert
Integrated Science 1A
Trimester 1, 2014
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Bell Ringer
How does the roller coaster today get up
to its highest point? (think about the
beginning of the ride)
Does it cost more to lift the roller coaster
if it is full of people?
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Agenda
1.
Bell Ringer
2.
Conservation of energy
3.
Spring potential energy lab
4.
Exit Slip
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Learning Targets
On your Bell Ringer
Sheet, write the
following:
We will relate kinetic,
spring, and gravitational
potential energy to
conservation of energy
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Law of conservation of energy
The
total amount of energy in a system remains
constant ("is conserved")
Energy
cannot be created or destroyed.
Energy
can only be changed from one form to
another
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Conservation of energy

It is impossible to convert one form of energy into
another without wasting some energy.
 Example: Automobile
engines typically waste more than
two-thirds of the total energy used, primarily through
heat.
 In
an isolated system, the energy will remain constant.
 Example: Thermos, cooler
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Reminder…
Kinetic energy – energy of movement
Potential energy – energy that is stored
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Spring potential energy lab
Answer questions 1a and 1b.
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KE
m
v
= Kinetic Energy
= mass
= velocity
SPE
GPE
= Gravitational
Potential Energy
m
= mass
g
= gravity (9.81
h
= height
𝑚
)
2
𝑠
k
x
= Spring Potential Energy
= spring constant
= amount of stretch or
compression
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Fill in the data!
How do we get these
values? (next slide)
Trials Mass (kg) Velocity (m/s) Height (m) GPE at peak KE just after
height (J)
popping (J)
1
2
Trial 1 = no coin, Trial 2 = one coin
Student fill in data
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Using the formulas
 𝐺𝑃𝐸
=𝑚∙𝑔∙ℎ
 𝐾𝐸
 Example:
 Mass
 Height
= 9.81
=
1
𝑚
2
∙ 𝑣2
 Example:
= 5 kg
 Gravity
Units for energy are
Joules (J)!
 Mass
𝑚
𝑠2
 Velocity
= 10 m
GPE = (5 kg) x (9.81
= 5 kg
𝑚
)
𝑠2
x (10 m)
KE =
1
2
= 14
𝑚
𝑠
x (5 kg) x (14
𝑚 2
)
𝑠
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Answer
questions 5a, 6a, 6b, 6c, 6d
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Read #7 on pg. 373 – 374 and fill in the table
Position above
table (m)
SPE (J)
KE (J)
GPE (J)
At rest on table:
Height = 0 m
Just after
popping:
Height = 0 m
Half way up:
Height = _____
At peak:
Height = _____
Each group will go up to the chalkboard and draw a diagram
SPE + KE + GPE (J)
+ Energy, Money & Conservation of energy
Think of the different types of energy as different
types of coins (pennies, dimes, quarters). If you have
$5 in quarters in a bowl, and replace one quarter
with 25 pennies, how much money is in the bowl?
What if you replace two quarters with 10 nickels?
The energy in a system can vary from kinetic, to
gravitational potential energy to spring potential
energy, but the total amount of energy would be the
same (CONSERVATION OF ENERGY!!)
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Look on pg. 375
1. When does the toy have the most SPE?
2. When does the toy have the most GPE?
3. When does the toy have the most KE?
4. What kind of energy does the toy have when it is halfway up in the air?
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Look on pg. 375
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Quick Reading
Read the first three paragraphs on page 375 and
answer the following questions in your notebook:
1.
Even though energy changes from one form to
another, what happens to the total energy?
2.
Why doesn’t a bouncing ball reach the same
height every time it bounces? Why does this
still support the conservation of energy?
Demo: energy of a
basketball
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Post-lab questions:
Answer questions 4, 6, 9, and 10
Challenge # 7, # 8
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Exit Slip
1.
A “pop-up” toy has 2 Joules of spring potential
energy before popping. How much kinetic energy
will the toy have just after leaving the table?
2.
Why can the second hill of the roller coaster not
be higher than the first hill?
3.
When the “pop-up” toy is flying up into the air,
what types of energy does it have?