iv. An object is 14 cm in front of a convex mirror. The image is 5.8 cm behind the mirror. What is the focal length of the mirror? A. 4.1cm

Question

iv. An object is 14 cm in front of a convex mirror. The image is 5.8 cm behind the mirror. What is the focal length of the mirror? A. 4.1cm B. 8.2 cm C. 9.9 cm D. 20 cm​

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Huyền Thanh 5 years 2021-07-13T15:31:08+00:00 1 Answers 317 views 1

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  1. thachthao
    1
    2021-07-13T15:32:13+00:00
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    Answer:

    C. 9.9 cm

    Explanation:

    The location of the object, u = 14 cm

    The location of the image, v = 5.8 cm

    The focal length of the mirror, f = Required

    The mirror formula for a convex mirror is given as follows;

    \dfrac{1}{u} -\dfrac{1}{v} = -\dfrac{1}{f}

    Therefore, we get;

    \dfrac{1}{14 \ cm} -\dfrac{1}{5.8 \ cm} =- \dfrac{41}{406 \ cm} = -\dfrac{1}{f}

    Therefore;

    f = \dfrac{406 \ cm}{41} \approx 9.9 \ cm

    The focal length of the mirror, f ≈ 9.9 cm

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