Transcript File

The Birds and the Bulbs
Tasers
https://youtu.be/ZfKWVrXKbn0
How do birds stay safe while holding
on to an electrically charged wire?
What makes electric charge flow?
What makes electric charge flow?
What makes electric charge flow?
What makes electric charge flow?
If the sphere is a conductor and
allows electrons to move freely,
what will the electrons do?
What makes electric charge flow?
If we held the electrons
in this position, what
kind of energy is this?
What makes electric charge flow?
If we held the electrons
in this position, what
kind of energy is this?
Energy that is stored and
held in readiness is
called potential energy.
What makes electric charge flow?
If we held the electrons
in this position, what
kind of energy is this?
Energy that is stored and
held in readiness is
called potential energy.
So, excess charges that are held in one
location have potential energy.
What makes electric charge flow?
So, excess charges that are held in one
location have potential energy.
What makes electric charge flow?
To understand what causes
electrons to flow through a
circuit, we can experiment
with batteries and light bulbs.
At each terminal of a battery,
excess charge builds up on
the terminals. Therefore,
there is potential energy at
each terminal.
What makes electric charge flow?
As you investigate, look
for which ways allow
charge to flow and which
ways do not. Think about
why nature is this way.
https://www.google.com/search?q=timer&oq=
timer&aqs=chrome..69i57j69i60j69i57j69i60j6
9i59j69i60.589j0j7&sourceid=chrome&ie=UTF8
What makes electric charge flow?
What did you observe about the battery and the
bulb?
What did you need to make electric charge
flow?
What makes electric charge flow?
• In order for electrons to flow through a
circuit, there must be two things:
– a place with excess electrons
(lots of potential energy)
AND
– a place where there aren’t as many
electrons (not as much potential energy)
• In other words, there must be a
difference in potential energy at two
points in the circuit.
• To sustain a flow of charge in a
conductor, one end must remain at a
higher potential energy than the other.
Electrons have no reason to
flow through this wire, because
there is no difference in
potential energy.
The same is true here… No
difference in potential energy.
Dam Analogy – A Difference in Potential Energy
Water flows just
like charge flows!
Low Potential
Energy
High Potential
Energy
Hoover Dam Collapse – Apocalypse (2006)
https://youtu.be/lfQEXLMr8Oo
Team Question: Will there be a flow of charges
here? Why or why not?
Team Question: Will there be a flow of charges
here? Why or why not?
Team Question: Will there be a flow of charges
here? Why or why not?
Lots of
potential
energy
Not much
potential
energy
Lots of
potential
energy
Not much
potential
energy
How do birds stay safe while holding
on to an electrically charged wire?
How do birds stay safe while holding
on to an electrically charged wire?
There is no
difference in
electric potential
energy on the
single wire!
“Voltage”
• A difference in electrical
potential energy allows
electrons to flow.
• The difference in
electrical potential
energy is called voltage
and is measured in
“Volts” (V).
• The more voltage you
have, the greater the
difference in potential
energy!
Exit Quiz
1. What kind of energy do electrons have if they
are held together in one location?
2. What do you need for electric charge to
flow?
3. How do birds stay safe while holding on to an
electrically charged wire?
BONUS: How do electrical outlets get charge to
flow through a wire?