Physics Mirrors and Reflection

light

A form of energy that travels away from the source

Reflection

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

Luminous object

Something that emits light.

Non-luminous object

An object that does not give out it's own light.

Real image

a copy of an object formed at the point where light rays actually meet

Virtual image

An image formed by the apparent intersection of rays

Lateral inversion

The apparent reversal of an image.

Diffuse reflection

When light hits off an object and scatters.

Regular reflection

When something is reflected off a silvered flat surface.

2 types of spherical mirrors

concave(caves in) and convex(bulges out)

Formula for a concave mirror / convex lens

Real: 1/f = 1/u + 1/v, Virtual: 1/f = 1/u - 1/v

Formula for a convex mirror / concave lens

1/u - 1/v = -1/f (f=focal point

Formula for magnification

Magnification = image size / real size M = v/u

Laws of reflection

1. The angle of incidence equals the angle of reflection.

2. The incident ray, the normal and the ray of reflection all lie on the same plane

Object placed outside the focus of a concave mirror

Image is real and inverted and magnified

Object placed inside the focus in a concave mirror (draw diagram)

Image is virtual and upright

Special Shoes: Object placed at focus in a concave mirror (draw diagram)

Image is at infinity

Diagram of an object in a plane mirror (relationship between Angle of incidence and reflection)

Angle of incidence equals the angle of reflection.

Rules of a convex mirror

1. from top of an object to mirror parallel to principle axis; back up as if coming from the focus on the other side.

2. From top of object hitting the mirror on the principle axis and back out at same angle on the other side.

Diagram of convex mirror.

No matter where the object is placed the rays appear to intersect behind the mirror - Virtual image.

How tall should a mirror be to see the full image of a person?

Half of the height of the person (Because the angle of incidence is equal to the angle of refraction)

Centre of Curvature

Centre/radius of the sphere from which the mirror is made of (Double the focal point)

Pole

The centre of a spherical mirror

Principal axis

A line running through the pole of a mirror or the optic centre of a lens

Focus/Focal point of a mirror

Halfway between the pole and the centre of curvature

Focal length of a mirror

The distance from the pole to the focus of a mirror