When you heat a substance
particles move faster and the
substance expands. Whn you cool a
substance particles move slower
and the substance contracts.
Conduction: Heat is passed by a vibration of
particles. Convection: Transfer of heat in a liquid
or gas due to less dense, warmer matter rising
and denser, cooler matter falling (particles).
Radiation: Heat movement in electromagnetic
waves, which can travel through a vacuum.
Radiated heat energy is transferred in a
transverse wave (moves at right
angles/vertical). Sound waves are
transferred as longitudinal waves (move
back and forth in the same direction the
wave is traveling.
Sound travels faster through solids, than liquids and
faster through liquids than gasses. Temperature also
affects the speed of sound. Sound travels faster through
warmer air than through cool air because particles
The number of vibrations a sound makes each second
is called the frequency of a wave, which is measured in
hertz (Hz). The wavelength of the sound is measured
between successive peaks and is measured in meters.
Volume is measured by amplitude, greater the
amplitude the more energy. Sound travels at 300m/s in
An object thar releases it own
light is called Luminous. A object
that doesn't release its own light
is called Non-lumnous.
According to the law of reflection,
the angle of incidence equals
(incoming ray) the angle of
When light is reflected off a very smooth surface
such as a mirror, it undergoes regular reflection.
This produces a clear image, all the rays are
reflected in the same direction. Most objects are
rough, so they reflect or scatter light in many
direction. This is called a diffuse reflection.
Refraction is the bending of light as it passes from one substance
into another substance. Light refracts because it travels at
different speeds in different substances.
Reflection is when
light is completely
reflected from the
boundary of two
substances; it occurs
when the angle of
incidence is greater