Download 8.8.a Conservation of Energy 1

8.8.a Conservation of Energy 1
SWBAT apply the Law of Conservation
of Energy to different situations in an
effort to calculate unknown variables.
1. A cart has 50 Joules of Kinetic Energy when
moving with a velocity of 4 m/s. What is the
cart’s mass?
2. A rock climber is 45 meters above the
ground. If the mass of the climber is 80 kg,
what is his potential energy?
3. A spring has a potential energy of 7 Joules
when compressed 13 cm. What is the
spring’s spring constant?
1)
2)
3)
4)
5)
6)
7)
C
A
C
240 N/m
0.57 J
2.7 N
38.4 N/m
8) 0.042 J
9) 247 N/m
10) 0.96 J
11) 5 J
12) 47.3 N/m
13) 4219 J
Mechanical Energy
Kinetic Energy (KE)
Non-Mechanical Energy
Internal Energy/Heat (Q)
Gravitational Potential
Energy (GPE or ΔPE)
Electrical Energy (W)
Chemical Energy
Elastic Potential Energy
(EPE or PEspring)
Nuclear
Can an object have
The more
Total than
Energy
one
is kind
the sum
of energy
of
at the same
time? all
What
the forms
are some
of energy
examples
present
that you
in a system
can think of?
ET = PE + KE + Q
Where is the formula for Total Energy?
The total energy of a system remains constant, although
energy may transform into another form.
In other words, energy can neither be created nor
destroyed.
This can be represented mathematically as:
∑ETi = ∑ETf
Total Initial Energy = Total Final Energy
Mechanical Energy
• Definition
• Science Joy wagon- skateboarder with spring
GPE=?
A 5kg ball is released from a height of 2 meters, slides
down a frictionless ramp, and compresses a spring with
a spring constant of 20N/m.
3.
4.
How
thefar
ramp
haswasn’t
the spring
frictionless,
compressed?
and
the
1. If
2.
What
is the
Gravitational
velocity
of been
thePotential
ball
in the
Energy
spring
only
J of EPEshown?
when
of the ball
position
shown?
inhad
the90
position
compressed, how much energy was
transferred into internal energy?
2m
x=?
v=?