Physics About the definition of electrical energy, mechanical energy, thermal energy, light energy,

Conversion of mechanical energy into chemical energy: Drilling wood for fire is first converted into internal energy, until combustion and chemical energy is released, and then chemical energy is converted into internal energy and light energy. There is the process of converting mechanical energy into chemical energy.

Smashing cannon (a kind of firecracker, which goes off when it falls), bullets and shells emit mechanical energy into internal energy and then release chemical energy from gunpowder**, so it can also be seen as an example of mechanical energy being converted into chemical energy.

The process of converting internal energy into chemical energy is as it is in fermentation.

Light energy is converted into mechanical energy, such as the formation of wind, sunlight irradiates the air so that the temperature and pressure of the air are different, and the air flows to form the wind, and wind energy can be regarded as a kind of mechanical energy. For example, the various tools powered by solar cells are examples of converting solar energy into electrical energy and then into mechanical energy.

Internal energy is converted into electrical energy, such as power generation equipment in thermal power plants.

Direct conversion examples:

1 Mechanical energy is converted into chemical energy: 2SO2 + O2 = 2SO3 This is a reversible reaction (to be learned in high school chemistry) compresses the volume of the reaction vessel, and mechanical energy is converted into chemical energy. If you don't understand, you can search for "Le Chatre's principle".

2.Internal energy is converted into chemical energy, and you have to have chemical knowledge, all endothermic reactions are like this, you can search for "endothermic reaction".

3. Light energy is converted into mechanical energy, and now there is another theory, called "solar sail", which is to directly use light energy to drive, this technology is too profound, Xiaosheng does not know much, you can search for "solar sail".

4. Internal energy is converted into electrical energy, thermocouple, in fact, is a thing that uses temperature difference to measure temperature, you can search for "thermocouple".

The Physical Superman team has you covered.

The first thing to understand is the "law of conservation of energy": energy does not arise out of thin air, nor does it disappear out of thin air, it only transforms from one form to another, or from one object to another. And the various forms of energy can be converted into each other (directly or indirectly) ...

Mechanical energy is converted into chemical energy, internal energy is converted into chemical energy, light energy is converted into mechanical energy, and internal energy is converted into electrical energy, These examples of direct conversion between various forms of energy may not be easy to cite but examples of indirect conversion abound: light energy chemical energy mechanical energy; Nuclear power plants: atomic internal energy, electrical energy, chemical energy (by electrolysis), etc.

Categories: Science & Engineering >> Engineering & Technology Sciences.

Problem description: Suppose you want to use a coin cell battery (alternating current) with a voltage of yes, connect a heating element, and require the heating element to generate a temperature of 50°C for 10 seconds.

1。How much power do you need for a coin cell battery?

2。What is the resistance of the heating element that generates heat?

3。How many milliampere-hours does a coin cell battery need to provide the required thermal energy continuously?

Thank you! If you haven't been exposed to physics for too long, you may not be able to express it in some places, so please point it out.

Analysis: 1 First of all, I have never seen an AC button battery, and it is assumed to be DC here.

2. The heating element must have volume and specific heat coefficient: hypothetical square centimeter, 1 calorie * cubic centimeter.

3. The ambient temperature and heat dissipation coefficient should be given: assuming that the ambient temperature is 20 degrees, there is no heat dissipation (good calculation).

Energy required to rise to 50 degrees = (50-20) * joules (Note: What is the joule coefficient converted to calorific card?) )

10 seconds to provide joules is available, and watts per second are required.

Knowing the voltage volt, it can be concluded that current = ampere.

It is difficult for a general coin cell battery to emit such a large current. And that's not even counting the heat dissipation.

Assuming that there is such a battery, the battery power should be the internal resistance below ohms, the lower the better, and the power above the ampere-hour or milliampere-hours.

The load resistance is in ohms.

If heat dissipation is taken into account, the battery power should be increased by 10 times, and the load resistance should be more than doubled. The challenge is that the battery needs to be able to generate the required current instantaneously.

In physics, kinetic energy and potential energy are collectively referred to as mechanical energy; The single defeat of the energy is Joule, referred to as Jiao Shen Ku, and the symbol for checking the cheats is J

So the answer is: mechanical; j．

Internal energy refers to the sum of the kinetic energy and the potential energy of the interaction between the molecules of all the molecules in the object, and the unit of internal energy is joules

Therefore, the answer is: all molecules do Lingna irregular movement; Joules

Chemical energy is the energy of the matter contained in an object.

Internal energy is mainly embodied in thermal energy;

Mechanical energy includes potential energy and kinetic energy.

Internal energy, mechanical energy, and chemical energy can be converted into each other.

When only gravity does the work, the kinetic energy is sum.

Gravitational potential energy. They can be converted into each other, but their sum does not change, that is, the mechanical energy is concurrent.

The subject or object of a judgment includes its entire extension. For example, in the proposition "all objects are in motion", the subject word "object" is circumferential because it speaks of all objects.

If an outspoken proposition asserts the full extension of the subject and the predicate, the subject or predicate is said to be circumferential in the proposition; Otherwise, it's an inconsiderate proposition type.

Proposition form. Subject-predicate.

A all s are p

Delay is not delayed.

E all s are not p

Weeks and rounds. I have some s that are p

Not thoughtful, not thoughtful.

o Some S are not P

Not thorough.

Conventional concept: Thermal energy is a basic form of energy, and all other forms of energy can be completely converted into thermal energy, and the vast majority of primary energy sources.

All of them are first utilized in the form of heat energy, so heat energy has an important meaning in energy utilization. The sum of kinetic and potential energy of the motion of the microscopic molecules that make up matter is called thermal energy. The macroscopic manifestation of this energy is the high or low temperature, which reflects the intensity of the molecular motion.

Broad concept: thermal energy (also known as heat, energy, etc., it is the energy source of life. The person's daily labor activities, sports, school studies, and all other activities, as well as the maintenance of normal body temperature by the human body.

All kinds of physiological activities consume energy.

Kinetic energy and potential energy are collectively referred to as mechanical energy, and thermal energy is a group of chemical energy. The essence of elasticity is not repulsion.

There are many ways to classify energy, such as light energy, mechanical energy, electrical energy, chemical energy, potential energy, thermal energy, and kinetic energy, which are classified according to specific applications, such as nuclear energy.