reflection and mirrors. sc.7.p.10.2 observe and explain that light can be reflected, refracted,...
TRANSCRIPT
Sunshine state standards
SC.7.P.10.2 Observe and explain that light can be
reflected, refracted, and/or absorbed. La.7.2.2.3
The student will organize information to show understanding (e.g. Representing main ideas through charting)
Page 324
Read My planet Diary on page 322
What are some of the things that you may see underwater?
How does the periscope work?
What are the different types of reflections?
REGULAR REFLECTION
Diffuse Reflection
REGULAR REFLECTION
Diffuse Reflection
Regular Reflection Definition:
A reflection occurs when parallel rays of light hit a smooth surface.
Rays: Visible light waves that are represented as straight lines.
All rays reflect at the same angle because of the smooth surface.
Regular Reflections
Image definition:An image is a copy of the object formed by reflected or refracted rays of light
Diffuse Reflection
Definition: A diffuse reflection occurs when parallel rays
of light hit an uneven surface. Each light ray obeys the law of reflection
but because the surface is uneven the rays reflect at different a angles which makes the image unclean or distorted.
Most objects have diffuse reflections or images even if they appear flat like paper or blades of grass.
Plane Mirror Definition:
A flat sheet of glass that had a smooth, silver-colored coating on one side.
The coating is smooth and regular and a virtual image is formed.
Virtual images Definition: An image that forms where light
seems to come from. Images that seem real but do not really exist,
such things “inside” the mirror. Virtual images produced by plane mirrors
are upright and the same size as an object.
Figure 2 page 324
1. Explain the similarities and differences of the ballet dancer in the picture.
2. Is the raised hand in the mirror an the dancers right or left hand?
Concave Mirrors
Definition: A mirror with a surface that curves inward like the
inside of a bowl. Optical Axis:
An imaginary line that divides a mirror in half (like the equator on the earth)
Concave mirrors create a focal point which is the point at which the rays that are parallel to the optical axis meet.
Concave mirrors produce Virtual and real images
Real images: Definition: forms when light rays actually meet. Real images are formed past the focal point and are upside
down. Real images can be smaller, bigger, or the same size as the
actual object. If the real image is produced past the object then the
real image will appear larger then the actual object. If the image is produced before the object then the
real image will appear smaller then the actual object. Virtual images created by concave mirrors are
upright and appear larger then the actual object
Complete Figure 3 on page 325
1. The image is real, upside down, and smaller than the object
2. The image is real, upside down, and larger than the object
3. The image is virtual, right-side up, and larger than the object.
Convex Mirrors
Definition: A mirror with a surface that curves outward
The reflected rays spread out after they reflect off the mirror so the focal point actually appears to form “inside” the mirror.
This causes the image formed by convex mirrors to be a virtual one and make the object appear smaller then the actual object.