Energy

Imagine placing a small stone on your head. Does it pain?

Now, imagine the same small stone falling on your head. Would you feel the pain?.

Of course, yes.  The reason is motion of the object (stone). Measurement of this motion is called Energy. You may even call it the measure of pain!

What is motion? 

Please refer to the following articles.

https://openneuron.blogspot.com/2024/05/temperature.html

https://openneuron.blogspot.com/2024/05/resonance.html

https://openneuron.blogspot.com/2024/05/motion.html

How do we visualize Energy?

Human beings require 2000 kilocalories per day. The food nutrition label above shows 220 kcal.

 https://www.fda.gov/food/nutrition-facts-label/how-understand-and-use-nutrition-facts-label 

How do we visualize the kilocalories of energy?

Example1 :

The tree is very tall. This is a very subjective description of the height of a tree. 

The tree is 30 feet tall. That gives is a very clear idea of how tall is the tree.

Example 2:

On a similar note, if a person has to climb stairs and reach 100 m height above ground level, what is the energy required?

You may use this simple formula.  Energy = Weight of the person x 10 x  height in meters.

If Weight of person = 70 kg, then energy required = 70 x 10 x 100 = 70 kJ = 16 calories

Example 3:

A stone of 2 kg falling on our head x height from which it falls.

2 kg x 10 x 1.5 m = 30J = 0.007 calories.

We may not even survive this event. however, it gives an idea of energy.

We considered only straight line motion to understand and visualize energy. The idea can be extended to rotation, wave and quantum motions. only the formulas would differ.

What is Power?

We classify plants as sun loving, shade loving etc. This leads us into the concept called power.

Power is measured in watts and is energy spent in 1 second.

Taking example 2, the person spends a total of 70000J to climb. If the person climbs in a low pace, he/she would not get tired. But if we ask them to run up the stairs, they might get exhausted quickly and may not even reach the top.

That;s the reason we require power as a concept. Lights, fans, cars, pumps are all specified in terms of power.

Some Facts about Energy

• Energy can neither be created nor destroyed
• Energy can be converted from one form to another
• Nature follows the path of least resistance

There are 7 forms of energy that govern the whole of universe.

Gravity, Electricity, Magnetism, Light, Sound, Heat, Chemical and Nuclear.

When plants perform photosynthesis, energy from sun light is converted into a valence bond (due to electric charges) within the sugar molecules (C6H12O6 for example) and stored in the plant. We shall refer to this as chemical energy.

Sugar (Glucose) Molecule 

When this bond (the horizontal and vertical lines) in sugar molecule is broken, energy is released back into the environment. This is what happens, when we consume food.

The following article provides a simple introduction to matter and bonds. 

https://openneuron.blogspot.com/2024/05/matter.html

Note:

A leaf has the ability to stop fast moving sunlight and hide it within its body. Some day human beings would create solar panels that would directly generate sugar.