# Can somebody explain potential energy to me?

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#1
Regarding potential energy with regards to phase changes I have several difficulties in understanding it so any help with these would be appreciated.

1) What is the potential energy?
2) Why does the potential energy only increase at certain points (e.g. water at 100 degrees celsius) and not for the entire period energy is being inputted?
3)Why does the kinetic energy not transfer to the potential energy and vice versa?
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4 years ago
#2
(Original post by JakeRStudent)
Regarding potential energy with regards to phase changes I have several difficulties in understanding it so any help with these would be appreciated.

1) What is the potential energy?
2) Why does the potential energy only increase at certain points (e.g. water at 100 degrees celsius) and not for the entire period energy is being inputted?
3)Why does the kinetic energy not transfer to the potential energy and vice versa?
1) Potential Energy is the energy possessed by a body by virtue of its state. This means that it has the ability to do work by converting potential energy into other forms of energy, such as kinetic energy. eg. an object on a cliff has gravitational potential energy because of its height. If you push it off the cliff it would start to fall, lowering the height, and gaining kinetic energy. In this case, gravitational energy is converted to kinetic energy. Another example is a spring being compressed, it has elastic potential energy which can generate kinetic energy to push an object foward.

2)Water at 100 degree celsius will absorb heat energy but it won't increase in temperature. This heat energy absorb is called latent heat, and is used to separate the bonds in the water molecules to form steam. The potential energy increases as the bonds are separated; If the bonds would reunite to become liquid again, it will release heat energy. Hence, there is potential energy in water vapour. On the other hand, if the water is at 30 degree celsius, applying heat to it would increase the temperature. Temperature is the average kinetic energy of all of the molecules in the substance. Therefore, if heat is applied and temperature increases, heat energy is converted into kinetic energy of the molecules. But if heat energy is applied at 100 degree celsius, the temperature doesn't increase, therefore heat energy is converted into potential energy in the bonds of molecules.

3) In most situations, it does. But potential energy can be converted into other forms of energy too, such as heat. This is called the Principle of Conservation of Energy, a well-known law in the universe.
To show you a situation of energy converting between kinetic and potential, firstly you throw a ball into the air, giving it kinetic energy. This ball slows down due to gravity, therefore there is a decreasing kinetic energy. As its height increases, its gravitational potential energy increases. It reaches a point when the velocity is zero, and it reaches its maximum height; in this situation, kinetic energy is zero, while gravitational potential energy is at its maximum. Then, it accelerates back down to the earth, gaining kinetic energy and losing gravitational potential energy.
1
#3
(Original post by NigelCws)
1) Potential Energy is the energy possessed by a body by virtue of its state. This means that it has the ability to do work by converting potential energy into other forms of energy, such as kinetic energy. eg. an object on a cliff has gravitational potential energy because of its height. If you push it off the cliff it would start to fall, lowering the height, and gaining kinetic energy. In this case, gravitational energy is converted to kinetic energy. Another example is a spring being compressed, it has elastic potential energy which can generate kinetic energy to push an object foward.

2)Water at 100 degree celsius will absorb heat energy but it won't increase in temperature. This heat energy absorb is called latent heat, and is used to separate the bonds in the water molecules to form steam. The potential energy increases as the bonds are separated; If the bonds would reunite to become liquid again, it will release heat energy. Hence, there is potential energy in water vapour. On the other hand, if the water is at 30 degree celsius, applying heat to it would increase the temperature. Temperature is the average kinetic energy of all of the molecules in the substance. Therefore, if heat is applied and temperature increases, heat energy is converted into kinetic energy of the molecules. But if heat energy is applied at 100 degree celsius, the temperature doesn't increase, therefore heat energy is converted into potential energy in the bonds of molecules.

3) In most situations, it does. But potential energy can be converted into other forms of energy too, such as heat. This is called the Principle of Conservation of Energy, a well-known law in the universe.
To show you a situation of energy converting between kinetic and potential, firstly you throw a ball into the air, giving it kinetic energy. This ball slows down due to gravity, therefore there is a decreasing kinetic energy. As its height increases, its gravitational potential energy increases. It reaches a point when the velocity is zero, and it reaches its maximum height; in this situation, kinetic energy is zero, while gravitational potential energy is at its maximum. Then, it accelerates back down to the earth, gaining kinetic energy and losing gravitational potential energy.
I think I was rather vague in the third question when I initially wrote it. What I meant was why, for example when heating a liquid causing it to boil) does the energy go into kinetice energy from 1-100 degrees but then at 100 degrees it goes into potential energy? Why does the enrgy not get distributed between them for the temperatures of 1-100 degrees?
0
4 years ago
#4
(Original post by JakeRStudent)
I think I was rather vague in the third question when I initially wrote it. What I meant was why, for example when heating a liquid causing it to boil) does the energy go into kinetice energy from 1-100 degrees but then at 100 degrees it goes into potential energy? Why does the enrgy not get distributed between them for the temperatures of 1-100 degrees?
Well, it actually does. Evaporation causes the water to turn into gas converting kinetic energy to potential energy. When the water gets hotter, the rate of evaporation increases. But when the temperature is at 100 degrees, kinetic energy usually stops increasing, as the water molecules vibrate and move at a velocity high enough to break the bonds, storing potential energy.
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