Wave: It is a temporary disturbance that transfers energy from one place to another. It divides into two:

1. Mechanical Wave

   Longitudinal wave: it is a particle that vibrates in the direction of propagation of a wave.

   Transverse wave: It is a particle that vibrates perpendicular to the direction of the wave.

2. Electromagnetic Wave

   Red is the electric field; and is called wavelength; blue is a magnetic field.

• Matter, such as solid, liquid, gas, or plasma that mechanical waves are traveling through is called Medium.

ELECTROMAGNETIC WAVE

They do not require a medium to propagate. It can also travel not only through the air and solid materials but also through a vacuum space. They travel as vibrations in electrical and magnetic fields.

Notes to remember:

• Electricity and magnetism can be static, but changing the magnetic field will induce an electric field and vice versa.

• The electric field and magnetic field of an electromagnetic wave are perpendiculars (at right angles) to each other.

• It travels with a constant velocity of c= 3.0x 10^8 m/s in a vacuum space.

CHARACTERISTICS OF WAVES:

1. Amplitude (A)

   The height of a wave is usually measured in meters (m). The greater amplitude of a wave, the more energy it’s carrying.

2. Wavelength

   The distance between 2 consecutive crests or troughs, and usually measured in meters(m)

3. Frequency

   The number of waves passing a point in a certain time. Gives a unit of Hertz (Hz).

4. Speed of light (c)

   All electromagnetic waves travel at the same speed which is about c=3.0 x 10^8 m/s through a vacuum space.

1. IONIZING RADIATION

   A type of energy released by atoms that travel in the form of Electromagnetic waves. Including Gamma rays and X-rays. This is more dangerous to humans than non-ionizing radiation.

2. NON IONIZING RADIATION

   the part of the electromagnetic spectrum where there is insufficient energy to cause ionization.

• When an electric field changes, so do the magnetic field. Why? because the magnetic field causes the electric field to change. This will result in an equal electromagnetic wave.

ELECTROMAGNETIC SPECTRUM

it is named for the range of electromagnetic waves when placed in order of increasing frequency.

$7 ELECTROMAGNETIC SPECTRUM:$

1. RADIO WAVES

   have the longest wavelengths but the shortest and lowest frequency.

2. MICROWAVES

   have a shorter wavelength and have a higher frequency of radio waves.

3. INFRARED RAYS (below red)

   shorter wavelength and higher frequency than a microwave.

4. VISIBLE LIGHT

   shorter wavelength and higher frequency than infrared.

5. ULTRAVIOLET RAYS

   it uses to kill bacteria.

6. X-RAYS

   Can penetrate most matter.

7. GAMMA RAYS

   carries the greatest amount of energy and it penetrates the most.

• Longest wavelength = Red light

• Shortest wavelength = Purple light