Download Energy laws - Shrewsbury Moodle

Learning objectives
What is energy?
Give examples of six forms of energy
Define two laws of energy
Explain energy metabolism
Explain the activities involved in supplying energy to the cells of the body
What is energy?
1. strength
2. the ability to do work
3. the capacity to produce a change within a system
Where can you see energy in this classroom?
Radiator: gives off heat energy (thermal)
Light: gives off energy in the form of light (radiant)
Cables: electrical energy; makes the computer work
Students writing: kinetic energy (motion)
Students eating: chemical energy
Throwing a ball of paper: gravitational energy
Students talking: sound energy
Other forms of energy
Potential energy (stored):
Atomic: nuclear energy
Forms of energy
1.
2.
3.
4.
5.
6.
7.
8.
kinetic (motion)
electrical
thermal (heat)
chemical
light
sound
gravitational
potential
http://www.teachertube.com/viewVideo.php?video_id=127807
Forms of energy
Kinetic energy is the energy of motion. We can observe it as the movement
of a person or an object, e.g. a person walking, throwing a ball, writing,
talking.
Potential energy: objects that are not in motion possess potential energy,
e.g. potential energy is stored in a stretched rubber band. When it is released
the stored energy is converted to kinetic energy.
Electrical energy is the presence and flow of an electric charge.
Thermal (heat) energy is generated by heat of any kind. It is caused by
increased movement of molecules in a substance, which in turns causes its
temperature to rise. When we rub our hands together the mechanical energy
increases thermal energy in the atoms in our hands. When we put our hands
over a hot stove we can feel thermal energy transfer. When we cook we burn
gas to convert the chemical energy into thermal energy.
Light is a form of radiant energy that we can detect with our eyes. The energy
in light comes from chemical energy, electrical energy and nuclear energy. It
is a combination of electrical and magnetic energy that travels very fast.
Gravitational energy: anything that is high up has gravitational energy.
When the skier goes down the hill, gravitational energy changes into kinetic
energy. Gravitational energy is stored and is therefore a kind of potential
energy.
Words:
Forms of energy
http://www.youtube.com/watch?v=TI2ItQIvexg&feature=related forms of energy
The energy laws
1. The Law of Conservation of Energy
The energy cannot be created or destroyed. This is the fundamental
principle of physics. The energy of an isolated system is constant over
time despite changes.
2. Transformation of energy
Energy can change its form within the system, e.g. chemical energy can
become kinetic energy. Energy can change its location within the
system, e.g.
Practical activities:
Students jump, clap their hands
1. What form energy do we need to be able to clap our hands?
2. What form of energy do we use when clapping our hands?
3. Into what other forms of energy is the kinetic energy turned?
(heat energy and sound energy)
1. What form of energy will you get from eating a breakfast in the
morning? Chemical energy
2. What type of energy are you using when riding a bicycle? Kinetic,
muscles change chemical energy into kinetic.
3. Chemical energy can be transferred into other forms of energy. Give
four examples of these forms. (kinetic energy when we move, heat
energy to keep warm, sound energy when we speak)
http://www.teachertube.com/viewVideo.php?title=Transforming_Energy&video
_id=241560
Why do we need energy?
The body needs energy for:
1. pumping of the heart
2. breathing
3. to push food along the intestines
4. to absorb food from the intestine into blood
5. to move urine from the kidney to the bladder
6. for the correct functioning of the nervous system
7. for the correct functioning of the brain
8. to replace the heat we lose to our environment
9. for growing
10. for tissues repair
What do we need to produce energy in our body?
1. food
2. oxygen
glucose + oxygen= energy+ water+ carbon dioxide
Use your textbook and the handout to form definitions of the following
concepts: metabolism, anabolism and catabolism.
Metabolism
Metabolism is a collection of …
reactions that take place in the
body’s cells to convert the fuel in the food we eat into the … needed to
power everything we do.
Metabolism is a
when we die.
…
process. It begins when we are conceived and ends
There are two distinct parts to metabolism:
(a) Catabolism is the part of metabolism in which substances are …
down. During … reactions complex organic substances are broken down
to form simpler ones. These reactions usually release energy that the body
can use in anabolic reactions. Some of them also provide chemical …
blocks that can be used for other substances. Examples of catabolic reactions
include the breaking down of … during respiration and the breakdown of
starch during digestion.
(b) Anabolism is about building and storing.
Anabolism is the part of
…
in which substances are built up. During
anabolic reactions, the body makes
…
organic compounds out of
simpler ones. These …
normally require a “push” in the form of energy.
Examples of anabolic reactions include making proteins from amino acids and
making glycogen from glucose. Anabolism:
1. supports the
…
2. contributes to the
3. supports the …
of new cells
…
of body tissues
of energy for use in the future
Words: reactions, catabolic, maintenance, metabolism, chemical,
complex, growth, storage, broken, constant, energy, building, glucose
The physiology of respiratory system in relation to energy metabolism
Respiration: a chemical process in which food is broken down to release energy.
Blood supplies glucose to the cells. Aerobic respiration also requires Oxygen.
The products of tissue respiration are Carbon Dioxide + water + energy.
C6H12O6
+ 6O2 = 6CO2 + 6H2O + Energy
Glucose + oxygen= carbon dioxide + water+ energy
Which type of energy does the balloon’s potential energy turn into when we let the
balloon go?
a) chemical
b) electric
c) kinetic
In which order does energy change from one type to another when you ride a bike and
then stop.
a) chemical, heat, kinetic
b) chemical, kinetic, heat
c) heat, kinetic, chemical
Which type of energy does a runner have?
a) electrical
b) elastic
c) kinetic