|Why does electricity have power?
|Question Date: 2017-12-01|
To understand how electricity has power, it is
helpful to first begin by thinking about how water
Imagine that you have two buckets of water
connected by a hose. If you raise one bucket above
your head and leave the other bucket on the floor,
then water will flow from the higher bucket to the
lower one (this is a concept called potential
energy). With this flow of water, you could do
all sorts of useful things like turning a turbine.
Roughly, this is how water "has power".
Electricity has power in the same way.
Batteries (or wall outlets) have two terminals one
labeled + and another -. You can think about the +
terminal as the water bucket raised above your
head, and the - terminal as the bucket on the
ground. When you connect these two terminals using
a wire, electrons (like water) flow from the +
to the - terminals. As with the water, these
flowing electrons can be used for useful tasks,
such as powering electronic devices like
Electricity only has power if there is a
difference in electrons between the + and -
terminals. This is why batteries eventually
run out. After all of the electrons have flown
from the + to the -, there is no longer any flow,
and there is no more power in the battery.
We can understand those in the picture of energy.
Energy can take different forms, such as
kinetic energy, potential energy, etc.
Energy is conserved and can be transform from one
Back to your question, electricity has power
because the existence of electric fields can
govern the motions of electrons and such energy
can be transformed and then it appears having the
power to do other things. .
I can give you an example:
billiard. I use the billiard pole and kick
the white ball, then it moves and hits the black
8. Because of the collision, the white ball stops
its motion and the black 8 starts moving. Here the
moving white ball behaves like the electricity. It
is moving and has the kinetic energy. After
the collision, the kinetic energy is transferred
to another ball and it is why it stopped its
motion and then the other ball started moving.
Just keep in mind, you have to kick the white
ball to make it move, so is electricity (you have
to generate electricity first).
We can generate electricity in different ways,
converting energies of other forms into
electricity. Then we use it to do different
things and transform the energy into other forms.
That is why the electricity had power.
Anything that contains energy has power ,
and the separation of electric charges consumes
energy, which means that the release of those
electric charges so that they can come together
again (i.e. electricity) produces energy.
It's the same reason why if you pick up a ball and
drop it, the ball will strike the ground harder
the higher you hold it when you let go. Gravity,
too, has power, and for the same reason as
I hope I answered your question.
It is useful to compare an electric current
flowing in a wire to water flowing in a river
. The water upstream has a higher potential energy
than the water downstream. I can convert the
potential energy into work by
allowing the water to flow through a waterwheel or
Work is the term that physicists use for the
type of energy that can be used to move
something. Similar to a waterwheel, I can
convert electrical potential energy into work by
running the electric current through a motor or
Power is actually a measure of the amount
of work done per unit of time, so it is
measuring the rate of work being performed. Doing
a lot of work really fast requires a lot of power.
Doing the same amount of work but slower requires
less power. Think again of water flowing in the
river. Water traveling in a large but slow-moving
river could only turn the waterwheel slowly (low
power). However, water traveling in a fast-moving
stream could turn the wheel muster faster (lots of
power). Similarly, electrical power measures
the rate that the electric current is being used
to perform some task.
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