What do they mean by "potential" energy? What does it apply to?

Question

I don't understand how it is measured.

Answer 1

Doc H is absolutely correct, but let's look at it from a different perspective.

Energy is the capability to do work or cause a change. It is in itself a potential, a "capability." When we say a tennis player is capable of winning the French Open, we are saying she has the potential for winning. We are not saying she has played (worked) and actually won it.

So in a very real sense, potential energy is the potential potential or, more clearly, the potential capability to do work or cause a change. This is yet another example of technical people making up definitions that would be best left to lexicographers who know what they are doing when it comes to defining the meaning of words.

Energy is not measured, it is a derived value. It's units are (kg-m/sec^2)m or kg(m/sec)^2. So the measurable characteristics of energy are mass (kg), length (m), and time (sec); which we can measure to derive a value representing that capability to do work or cause a change we call energy.

Using Doc's example, PE = mgh = potential energy within a gravitational field, we can measure mass, the acceleration due to gravity, and height the mass has been raised. With that we come up with a value for PE, the potential capability to do work or cause a change. We got that "potential" by doing work in the first place to get that mass (m) to a height (h) against the force of gravity we call weight. In other words, PE = Wh; where W = mg is the weight of the mass.

Clearly, by raising the mass, we can push it over the side of, say a table top, so that the mass will fall back down to wherever it was raised from (e.g., the ground).

And if we were to attach something to the mass so that the something was pulled along the table top, we would be doing work on that something. In other words, as the mass is falling to the ground the potential energy it had is "converted" into kinetic energy (KE) and that capability does work by pulling that something across the table top.

So, to answer your question, PE applies to a potential capability to do work or cause a change. It is not measured directly as it is a derived value based on mass, length, and time, which are measurable.

Answer 2

Potential energy refers to the energy possesed by an object when it is at a height. Objects at rest on ground are not taken as obj.s having potential energy.
e.g. When a stone is dropped from a ht.-
1. Before dropping,it has potential energy,meaning that it has energy which can be used to do work.
2. As it drops down,it posseses kinetic energy which ultimately reduces to 0 when it stops on the ground and REGAINS its potential energy.

Answer 3

An object can store energy as the result of its position. For example, the heavy heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of position is referred to as potential energy.

Potential energy exists whenever an object which has mass has a position within a force field. The most everyday example of this is the position of objects in the earth's gravitational field.

The potential energy of an object in this case is given by the relation:

PE = mgh

where:

PE = Energy (in Joules)
m = mass (in kilograms)
g = gravitational acceleration of the earth (9.8 m/sec2)
h = height above earth's surface (in meters)

For a more detailed exlanation I suggest you visit the following website:

http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/u5l1b.html

Good luck!

Answer 4

Potential means that the energy is not being used but could be.

Like in EMF, there is a potential between two legs of an electrical circuit, but it is only potential until some sort of connection is made.

Answer 5

it's energy of position and it's dependent on height above earth surface. it's measure using the formula PE=W*H.
examples: a suspension bridge, a waterfall, you standing on a diving board on the water, etc.

Answer 6

Plain and simply potential energy is stored energy.

Answer 7

it is the energy of the body due to its position or configuration.
e.gthegravitational P.Eof a body depends on its height above the surface.the elastic P>E. of a spring depends on its alongation from the original unstretched length.the bow under tensionand the wound up spring of a clock.have.P.E.

Answer 8

Energy that you do not see but it is there. Like the energy on pound of weight has when you drop it on your toes.

Answer 9

I do not know, to me it means energy that could have been used if someone knew how to.