chapter 5, section 7. hw: p 555 ptg 5.7 #1-6, 8 learning objectives compare and contrast real and...
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CURVED MIRRORSChapter 5, Section 7
HW: p 555 PTG 5.7 #1-6, 8 Learning Objectives
Compare and contrast real and virtual images
Describe focal length Success Criteria
Identify the focal point and the focal length of a curved mirror
Observe virtual images in a convex mirror
Observe real and virtual images in a concave mirror
Measure and graph image distance vs. object distance for a concave mirror
Do Now:Write LO and SC
on new left pagep 548
WDYS/WDYT Agenda:
Do NowLab 5.7 Summary
Investigation 5.7 #1 and #2
#3-9
#10-12
Record observations with concave and convex mirror
Class demo under document camera. Students record responses for #8 and #9
Students complete using same steps as 3-9.
Investigation 5.7 continued #13-15 Teacher
demo with finding image
#16 -17 Students use same process with object that is outside window
Students record observations in data table like the one found in #14
Students record observations in journal and thoughts on convex mirrors
HW: p 555 PTG 5.7 #1-6, 8 Learning Objectives
Compare and contrast real and virtual images
Describe focal length Success Criteria
Identify the focal point and the focal length of a curved mirror
Observe virtual images in a convex mirror
Observe real and virtual images in a concave mirror
Measure and graph image distance vs. object distance for a concave mirror
Do Now:How do the images
of concave and convex mirrors compare? How do you know?
Agenda:Do NowPhysics Talk 5.7Summary
Physics Talk 5.7 What is a real
image?
What is a virtual image?
An image that will project on a screen – it has an actual image location
An image that will not project on a screen – the image only appears to be coming from that location
Physics Talk 5.7 What is a concave
mirror?
What is a convex mirror?
A curved mirror in which the reflecting surface caves in
A curved mirror in which the reflecting surface bulges out
Physics Talk 5.7 What is the
relationship between the angle of incidence and angle of reflection?
The angles are equal. This allows us to draw ray diagrams that illustrate how the light is moving
Studying Ray Diagrams Illustrating light 3 rays
coming toward concave mirror
1. This ray is parallel to principal axis. This same ray reflects through the focal point
2. This ray approaches the center of the mirror and reflects with the same angle
3. This ray goes through focal point first, hits the mirror, and reflects parallel to the principal axis
All 3 rays must be present in ALL ray diagrams!!!
Studying Ray Diagrams The place where all
3 rays meet is the top of the image
The rest of the image is between that point and the principal axis
All 3 rays must be present in ALL ray diagrams!!!
Study the Diagram This is a similar
situation, except the object is farther from the mirror
This demonstrates the different sized images you saw in the lab
Find and name all three rays
Diagram with Virtual Image
If the object is closer to the mirror than the focal length, it will produce a virtual image
Diagram with Virtual Image
1. This ray runs parallel to the principal axis and through the focal point
2. This ray goes from the object in the angel of the focal point and will reflect parallel to the principal axis
3. This ray will leave the object and reflect off the mirror where the principal axis and mirror meet with the same angle
Where do the rays meet?
Physics Talk 5.7 Where did the rays
meet in the diagram?
Where can the image be found?
The rays never met, which means there is no real image!
The virtual image appears to be behind the mirror where the extended rays meet
Physics Talk 5.7 How does this
compare to plane mirrors?
With plane mirrors, the virtual image is identical in size to the object
With curved mirrors, the virtual image can be a different size
Physics Talk 5.7 How does this work
for convex mirrors?
Find the rays
What kind of relationship is it?
We can tell by looking at the graph, that it has the shape of a hyperbola.
This shape tells us we have an inverse relationship between object distance and image distance
End of Section Questions Checking Up p 552 What do you think
now? p 554
Practicing Ray DiagramsPTG #7, 9-12 as a class
Ray Diagram Practice Worksheet
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