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A disturbance that transfers energy from one place to another.


The distance between two corresponding parts of a wave.


The highest part of a transverse wave.


The lowest part of a transverse wave.


The distance between the rest position and the highest or lowest part of a wave.


The bouncing back of an object or a wave when it hits a surface through which it cannot pass.

Law of Reflection

Angle of reflection = Angle of incidence.

Normal Line

The correct trajectory of the incident ray.

Incident ray

The ray which is entering the surface.

Reflected ray

The ray which is reflected or bounced of the surface.

Angle of Incidence

The angle at which the incident ray is entering the surface.

Angle of Reflection

The angle at which the reflected ray is bounced off, and is equal to the angle of incidence.
13. Plane mirror: a surface capable of reflecting a ray.

Plane Mirror

A flat mirror that produces an upright, virtual image the same size as the object.


The bending of waves as they enter a new medium at an angle.

Convex Lens

A lens that is thicker on the center than at the edges.

Concave Lens

A lens that is thinner in the center than at the edges.

Electromagnetic Spectrum

The complete range of electromagnetic waves placed in order of increasing frequency.

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