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PHYS 1CPROBLEM SESSION

COURSE INSTRUCTOR: DR. FRANK WUERTHWEIN

We’ll start at 7:00Week 7

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Quiz Preparation Guidelines:

1. Do the practice quiz questions

2. Do the assigned homework

3. Bring your own calculator

4. Organize your own cheat sheet

5. Remember your exam number

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Quiz Reminders:

1. The cheat sheet should be letter-sized

and used only on one side.

2. You’re not allowed to use someone else’s

calculator or cheat sheet during the quiz.

3. Only your Scantron will be collected

when you are finished.

Check Your Grades Online

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Send Your Feedback Online

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Part I

Practice Questions

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• A)

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Part I

Practice Questions

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• A)

Spherical Mirrors

• Focal Point / Center of Curvature

• Ray Diagrams

• Parallel to the principal axis reflected to the focus

• Through the focus reflected parallel to the principal

axis

• Through the center of curvature reflected back on

itself

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Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

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Spherical Mirrors

• Concave Mirrors

• P < F : Upright , enlarged , virtual

• P = F : Impossible to see the image (infinitely faraway)

• C < P < F : Inverted , enlarged size , real

• P = C : Inverted , same size , real

• P > C : Inverted , reduced size , real

• Ray diagram is risky in the quiz!

(Why?) 9

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

Spherical Mirrors

• Convex Mirrors

• P < |F| : Upright , smaller , virtual

• P = |F| : Upright , smaller , virtual

• C < P < |F| : Upright , smaller , virtual

• P = C : Upright , smaller , virtual

• P > C : Upright , smaller , virtual

• Ray Diagram Qualitative

• Mirror Equation Quantitative 10

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

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Ch26

Question 2

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• (i) a c

(ii) e

(iii) a c

Ch26

Question 9

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• (C)

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Mirror Equation

• Quantitative - When it comes to:

• Location (where is the image / what is the focal length)

• Magnification (the size / factor of the image)

• Signs really matter

Put it on the cheat sheet 13

1

𝑝+1

𝑞=1

𝑓

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

14Carefully copy it onto your cheat sheet!

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Magnification

• Orientation

• Positive – Upright

• Negative – Inverted

• Size of the image

• M < 1 : The image is smaller

• M = 1 : The image’s size is the same as the object’s

• M > 1 : The image is bigger15

𝑀 =ℎ′

ℎ= −

𝑞

𝑝

ℎ′ = 𝑀ℎ

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

Ch26

Question 6

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• (d)

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Thin Lenses

• Lens-makers’ equation

• R1 / R2 is positive when the center of

curvature is in back of lens.

• R1 / R2 is negative when the center of

curvature is in front of the lens. 17

1

𝑓= (𝑛 − 1)(

1

𝑅1−

1

𝑅2)

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

Thin Lenses

• f > 0 Converging Lens

• f < 0 Diverging Lens18

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𝑓= (𝑛 − 1)(

1

𝑅1−

1

𝑅2)

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

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Thin Lens – Ray Diagram

• Ray Drawing Rules

• Parallel to the principle axis

refracted and through the focal point on the back side

• Through the focal point on the front side

refracted and parallel to the principle axis

• Through the center of the lens

continues in a straight line (no turns) 19

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

Thin Lens – Ray Diagram

• Converging Lens

• P < f : Upright , bigger , virtual

• P = f : No image (infinitely faraway)

• f < P < 2f : Inverted , bigger , real

• P = 2f : Inverted , same size , real

• P > 2f : Inverted , smaller , real

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• Diverging Lens

• P anywhere : Upright , smaller , virtual

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

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Ch26

Question 4

21• (i) e (ii) a c

Thin Lens Equation

• As well as the magnification formula

• Again, signs really matter.22

𝑀 =ℎ′

ℎ= −

𝑞

𝑝

1

𝑝+1

𝑞=1

𝑓

Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

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23The table is different from that for mirrors!

Sign Convention for Thin Lens Equation

Ch26

Question 3

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• (b)

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Ch26

Question 8

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• 1.05

Ch26

Question 11

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• (C)

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Practice QuestionsPart 2

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Spherical Mirrors

Mirror Equation

Thin Lenses

Thin Lens Equation

Practice Problems

Part 2

Practice Questions

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• D)

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Part 2

Practice Questions

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• B)

Part 2

Practice Questions

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• B)

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Part 2

Practice Questions

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• A)

Part 2

Practice Questions

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• A)

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Part 2

Practice Questions

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• A)

Good Luck!

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