Curved Mirrors(Two Kinds)

C: Centre of Curvature (2F)V: Vertex

PA: Principal AxisF: Focal Point

f : focal length (Distance FV)

1. Concave MirrorsIf the curvature is inward (“like a cave”), it is

called “concave”. This is like having the inside of a hollow sphere as a mirror.

Also called “converging mirrors” because light converges (towards) on the focal point

CONVERGING (CONCAVE) MIRROR Ray

#Incident Ray Reflected Ray Diagram

1 Parallel to Principal Axis (PA)

Through the Focal Point (F)

2 Through the Focal Point (F)

Parallel to Principal Axis (PA)

3 Through the Centre of Curvature (C)

Through the Centre of Curvature (C)

VC F PA

VC F PA

VC F PA

1. Locate the image in a ConcaveMirror when the object before C.

VC F PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

object

image

2. Locate the image in a ConcaveMirror when the object is at C

VC F PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

object

image

3. Locate the image in a ConcaveMirror when the object is between C and F

VC F PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

image

object

4. Locate the image in a ConcaveMirror when the object is at F

VC F PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

object

NO Image!!!(Parallel Lines)

5. Locate the image in a ConcaveMirror when the object is between F and V

VC F PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

object

ImageBehind mirror

2. Convex mirrors

• If the curvature is outward, it is called “convex”. Central Tech and many stores have these mirrors for safety –

• Also known as “diverging” mirrors – light goes away (diverges) from the focal point.

DIVERGING (CONVEX) MIRROR Ray # Incident Ray Reflected Ray Diagram

1 Parallel to Principal Axis (PA)

Away from the Focal Point (F)

2 Towards the Focal Point (F)

Parallel to Principal Axis (PA)

3 Through the Centre of Curvature (C)

Through the Centre of Curvature (C)

V CF PA

V CF PA

V CF PA

1. Locate the image in a ConvexMirror when the object is in front of the Mirror

V CF PA

Describe the Image (SALT)S: Smaller, Same Size or LargerA: Inverted or UprightL: Behind or In-front of mirror T: Real or Virtual or No Image

object

image