Plane Mirror Reflection

Task 1

A plane mirror is a mirror with a flat (planar) reflective surface.[1][2] For light rays striking a plane mirror, the angle of reflection equals the angle of incidence.[3] The angle of incidence is the angle between the incident ray and the surface normal (an imaginary line perpendicular to the surface). Therefore, the angle of reflection is the angle between the reflected ray and the normal and a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects. One of the important characteristic of the image is that it is laterally inverted. It means if you raise your left hand it would appear in the plane mirror that you have raised your right hand.

A ray diagram  the mirror is drawn

The image formed is said to be real because the rays of lighted from the object pass through the film and inverted (upside down). (Passmyexams.co.uk, 2018)

Concave always produce images that are virtual, upright and diminished (smaller) in size compared to the object. The image always appears to come from the same side of the lens as the object.

Ray diagrams for diverging lenses follow similar conventions to those for converging lenses, but how the location of the image is determined is slightly different.

Ray diagrams for diverging lenses follow similar conventions to those for converging lenses but how the location of the image is determined is slightly different.

Three rays are drawn:

1. A ray passing parallel to the principal axis and being refracted away from the principal axis.

2. A ray directed at the principal focus behind the lens - but being refracted by the lens so that it runs parallel to the principal focus after leaving the lens.

3. A ray passing in a straight line through the centre of lens without being

As a sound wave moves from the lips of a speaker to the ear of a listener, particles of air vibrate back and forth in the same direction and the opposite direction of energy transport. Each individual particle pushes on its neighbouring particle so as to push it forward. The collision of particle #1 with its neighbor serves to restore particle #1 to its original position and displace particle #2 in a forward direction. This back and forth motion of particles in the direction of energy transport creates regions within the medium where the particles are pressed together and other regions where the particles are spread apart. Longitudinal waves can always be quickly identified by the presence of such regions. This process continues along the chain of particles until the sound wave reaches the ear of the listener. A detailed discussion of sound is presented in another unit of The Physics Classroom