THE BATTLE FOR ENERGY
KAMIL FEDUS Katedra Dydaktyki Fizyki
Wydział Fizyki, Astronomii i Informatyki Stosowanej Uniwersytet Mikołaja Kopernika w Toruniu
Project number: 2021-1-IT02-KA220-HED-000032259
e4 higher Educational tools for an Embodied & creative Education on Energy
•You can hear energy as sound.
•You can see energy as light.
•You can feel the energy as heat or a touch of the wind.
•Energy is also electricity, thanks to which light bulbs shine, cell phones, washing machines, refrigerators, and computers work….
•More puzzlingly, energy is also contained in food, fuel, and mass (that is, in the nuclei of the atoms we are made of).
…. in other words, energy takes many forms.
Energy is all around us!
How is it possible that energy is involved in so many different activities?
• In the simplest terms, energy can be defined as the ability to do work.
• Energy can be counted, measured, described, and even valued - but it is not accessible to precisely define it.
What is energy?
Why do bodies move?
Because they have energy!
We can say that movement is energy.
This form of energy is called kinetic energy.
E K = 1
2 mv 2
Kinetic energy
Potential energy is stored energy.
(a) Energy may be stored as work is carried out by:
•rubber stretching.
•spring stretching.
•lifting the object high up (relative to the Earth, E = mgh).
(b) Energy can also be stored in food, fuel, nuclei and electric fields.
Potential energy
R. L. Jaffe, Physics of energy
What is the minimum energy needed to climb „Śnieżka” (mountain in Poland)?
E = 100 kg ´10 m
s
2´1600 m=1.6 MJ
E = mgh
Is it a lot or a little?
… it derives its energy for movement from chemical energy - only that contained in the fuel (not in food).
Chemical energy heat movement (kinetic energy)
The car is like a human being ...
How much energy is consumed during the journey from Gdańsk to Kraków?
• distance = 600 km
• combustion rate = 10 L / 100 km
• total fuel consumption = 60 L
• the energy content of gasoline= 30 MJ /L
• total energy used = 1800 MJ !!!!
1800 MJ
heat (75%):
1350 MJ
kinetic energy (0.4%): 0.7 MJ
gravitational potential energy (0.2%):
0.26 MJ
braking, friction, air resistance (24.4%):
449.4 MJ
The sun - the main source of energy
on Earth
Energy is never lost - energy only changes its form!
When someone says, "we have lost or used up energy," he means that energy has been converted into another, less useful form of energy.
Energy transformations
Energy transformations
movement heat
light movement
Light as a form of energy
light electrical energy
Sun Solar cell Heat
Electricity
chemical energy electrical energy
How to make a battery:
