Refraction and lenses
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
1,133
On Slideshare
1,133
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
19
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Refraction and Lenses
    7SCIENCE
  • 2. Review: What is refraction?
    Refraction occurs when light bends
    Light bends as it passes from one substance to another
    Ex. A straw in a glass into water
    Refraction can be caused by a lens
    A lens is a transparent object with at least one curved side that causes light to bend
    More curved sides = more light bends
  • 3. Lenses
    Concave and convex lenses form images OPPOSITE to that in concave and convex mirrors
    Convex lens
    Thicker in the center than at the edgesex: magnifying glass
    Concave lens
    Thicker at the sides that in the center
    ex: glasses for people that cannot see far objects
  • 4. Convex lenses
    Light rays travelling through a convex lens are bent so they meet at a focal point
    Image formed is similar to that of a concave mirror
    If the object is 2+ (or more) focal lengths from the lens, the image appears inverted and smaller
    If the object is closer to the lens than one focal length, the image is upright and larger
  • 5. Concave lenses
    Light rays travelling through a concave lens are bent and spread away from each other, do not meet
    Image formed is similar to thatof a convex mirror
    Image formed is upright and smaller than the object
    Ex: eyeglasses if you cannot see far
  • 6. Which pictures show a concave lens? Convex lens? How do you know?