2. ENERGY
Energy is the capacity for doing work or to produce
heat.
Energy cannot be created or destroyed, it can
only be transformed from one form into another.
Types of material systems depending on the
transference:
Open system: You are able to exchange matter and
energy.
Closed system: You can exchange energy (as heat or
work), but not matter.
Isolated system: You can’t exchange any of heat, work, or
matter with the surroundings.
Heat and work can produce transformations in
matter.
3. A body has:
Potential Energy: stored energy.
Energy
Kinetic Energy: the energy of motion. Ex: A roller
Energy
coaster.
Substances like wood, coal, oil, and gasoline have
stored energy because of their chemistry they can
burn.
4. FORMS OF ENERGY
Mechanical
Electrical
Thermal
Electromagnetic
Chemical
Nuclear
Internal
Energy can be
transferred, or
converted, from
one form to
another!
5. MECHANICAL ENERGY
Energy associated with the motion of an object.
(Kinetic and potential energy)
Chewing
Frog Dancing
6. THERMAL ENERGY
Total energy of the particles in a
substance or material.
All objects give off
thermal energy
Ice cream melting
gains thermal
energy
8. INTERNAL ENERGY
It is the total energy contained by a
body, related to atoms, molecules etc.
9. ELECTRICAL ENERGY
Moving electrical charges that
produce electricity and energy.
Lightening
Batteries
10. ELECTROMAGNETIC ENERGY
Energy that travels in waves
Visible light
UV Rays
Microwaves
Radio
11. NUCLEAR POWER
Energy stored in the nucleus of an
atom from fission or fusion
Sun
Stars
Nuclear Power
Plant
12. SOURCES OF ENERGY
Renewable energy: It comes from natural resources
such as sunlight, wind, rain, tides, and geothermal
heat.
Non-renewable energy: resources which can’t be
used again and again because they run out. Ex: Fossil
fuels.
13. ACTIVITIES
1.What happens during any change?
2.Write an example of open, closed and isolated system.
3.What type of material system (open, closed isolated) is
a pressure cooker with food inside which is being
heated:
a) Before the security valve expels water vapour.
b)When the security valve expels water vapour.
4. What’s energy?
5.Two bodies, A and B, are isolated from the
environment. If body B gains 500 J of energy, what
has happened to body A?
14. 6.Name the type of mechanical energy a body has
when:
a) It’s at rest on the top of a roof.
b) It reaches the ground at a speed of 3 m/s.
7.What’s a nonrenewable source of energy? And
renewable? Give examples of both.
8.In what units are heat and work measured?
9.Fill in the blanks using these words: joules-
transformed-energy-material system-destroyed-
same.
_______is the capacity that a _______ has to produce
changes. Energy is measured in______ In any energy
transfer, the total amount of_______ before the transfer
remains the__________ as the total amount
of_______afterwards. Energy is not______or________,
it’s just___________.