ENERGY!
Fill in the gaps:
Reflection
Refraction
Through matter
Rarefying
Straight
Compressing
Vacuum
Kinetic
Vibrations
• Light energy always travels in ________ lines.
• When light hits a prism, it is bent, this is called _____________
• When light bounces off a surface, this is called______________
• Sound energy has to travel _____________, but light can travel
through a ________.
• Sound is caused by air particles __________ and __________.
• Sound is caused by ________.
• Both sound and light are types of ___________ energy.
Energy:
• What is it?
• What does it do?
• What can’t it do?
• Give at least 37 types of
energy:
Energy can neither be created nor destroyed, only converted into other forms.
There are two distinct types of energy:
• Kinetic energy: The energy of movement. This includes:
- Heat energy: The movement of particles
- Light energy: The movement of photons
- Sound energy: The movement of air particles
- Electrical energy: The movement of electrons
• Potential energy: The energy stored in a system. This includes:
- Gravitational potential: The energy stored in something high
- Chemical potential energy: The energy stored in chemical bonds
- Elastic potential energy: The energy stored in particles which are
stretched or compressed
- Nuclear potential energy: The energy stored in the bonds between
subatomic particles.
https://www.youtube.com/watch?v=6qF_fzEI4wU
Heat transfer: Three ways heat is supplied
• There are three ways heat is transferred to the environment:
Convection, Conduction and radiation. Which is which?
https://www.youtube.com/watch?v=e7kmmj
_qRss
Sound energy:
Is it potential or kinetic?
What is moving?
Sound energy is the movement
of particles due to a vibrating
source.
Sound energy:
The wavelength of sound is the gap
between vibrations.
The frequency of sound is how often
the waves move through a point. This is
also known as the pitch.
What would you hear if the gaps
between waves were shorter?
What would you here if the waves
moved through a point more quickly?
http://www.physics-chemistryinteractive-flashanimation.com/electricity_electromagn
etism_interactive/oscilloscope_descripti
on_tutorial_sounds_frequency.htm
Sound energy:
Sound can move in a variety of ways
depending on what it moves
through.
Reflection occurs when sound hits a
flat, solid surface.
Absorption occurs when sound hits a
soft surface.
Diffusion occurs when sound hits a
lumpy, rough surface.
The science of sound is called
acoustics.
What should we do to soundproof
this wall?
The bell jar
• Now that we know about sound:
Aim: To demonstrate the effect air
particles have on sound
Method: Remove the air from a jar and
ring a bell.
Hypothesis: ?
Results: ?
Discussion: ?
The independent variable here is:
The dependent variable is:
The volume of the bell is measured in
decibels
Light energy:
Is it potential or kinetic?
What is moving?
Light energy is the movement
of photons through space.
Light, just like sound, travels as a
wave. It travels at 3X 10^8 m/s.
Light is a form of electromagnetic
radiation.
Light energy:
A rainbow happens because white
light disperses.
Dispersion is what happens when
light moves through a medium,
and the different wavelengths
travel at different speed.
Light energy:
Light can be:
Reflected: It bounces off at the
same angle that it hits.
Refracted: When light is
transmitted through a surface, it
changes direction slightly.
A concave lens or mirror is bent
inwards.
A convex lens or mirror is bent
outwards.
Eyes have lenses in them. These lenses are used to refract light onto your retina, where your
light detecting cells are.
A short sighted person has a lens which is too convex. This can be corrected with a concave
lens in the glasses.
A far sighted person has a lens which is not convex enough. This can be corrected with a more
convex lens in the glasses.
Use the light boxes to simulate a short sighted and long sighted person, and draw a diagram.
Use another lens to correct it, and show what happens in the diagram.
Light Box:
Observe what happens when you change the lenses.
Draw a ray diagram of what you create.
Explain what concave and convex lenses do to the ray of light:
Quiz time: Winner gets a prize
Question 1:
Which of the following is a type of potential energy?
A) Electrical energy
B) Heat energy
C) Elastic energy
D) Kinetic energy
Quiz time: Winner gets a prize
Question 2:
The energy we get from the sun is:
A) Only heat
B) Electromagnetic and heat
C) Only potential energy
D) Only light
Quiz time: Winner gets a prize
Question 3:
A light is efficient if it:
A) Heats you up as well
B) Turns 85% of it’s electrical energy into heat
C) Turns most of it’s electrical energy into light
D) Turns it’s electrical energy into dance music
Quiz time: Winner gets a prize
Question 4:
If Mac fell off of a cliff, he would have the most potential energy:
A) Before he fell
B) When he’s travelling at his terminal velocity
C) Just before he hits the ground
D) Just after “splat!”
Quiz time: Winner gets a prize
Question 5:
When you clap your hands:
A) You’re turning heat energy into light energy
B) Energy is being transferred, not transformed
C) You are transforming kinetic energy into sound energy
D) You’re happy and you know it
Quiz time: Winner gets a prize
Question 6:
Conduction only occurs:
A) When somebody is leading an orchestra
B) When particles are packed close enough together to transfer kinetic
energy to each other
C) When air particles move up and down
D) In the sun
Quiz time: Winner gets a prize
Question 7:
This student:
A) Just saw a Ghost
B) Is demonstrating Kinetic-Chemical-Kinetic energy transformations
C) Is demonstrating Kinetic-Electrical-Kinetic energy transformations
D) Is demonstrating Electrical-Kinetic-Electrical-Kinetic energy
transformations.
Question 8:
By standing up, this cat has:
A) Increased it’s kinetic energy
B) Increased it’s elastic potential energy
C) Increased it’s gravitational potential energy
D) Signalled the apocalypse
Question 9:
When a boy is bouncing on a trampoline:
A) He has the most Kinetic energy at the top of his jump, and the most
elastic potential energy.
B) He has the most Kinetic energy in mid air, and the most gravitational
potential
C) He has the least gravitational potential at the bottom of his jump,
and the most elastic potential
D) He is the happiest he will ever be
Question 10:
There are three ways of transferring energy to the environment.
Choose the most correct answer.
A) Radiation heat, it goes through the skies
B) Convection fluid rise, it’s where the heats applied
C) You touch the fire, Conduction heat goes by
D) All of the above