A person 1.8m tall stands 0.75m from a reflecting globe in a garden. PART A If the diameter of the globe is 16cm , where is the image

Question

A person 1.8m tall stands 0.75m from a reflecting globe in a garden.
PART A If the diameter of the globe is 16cm , where is the image of the person, relative to the surface of the globe?
PART B How large is the person’s image?

in progress 0
Thu Giang 5 years 2021-07-26T15:38:23+00:00 1 Answers 29 views 0

Answers ( )

  1. RuslanHeatt
    0
    2021-07-26T15:39:35+00:00
    Reply

    Answer:

    1. The image of the person is 1.41 m, virtual and formed at the back of the surface of the globe.

    2. The person’s image is 3.38 m tall.

    Explanation:

    From the given question, object distance, u = 0.75 m, object height = 1.8 m, radius of curvature of the reflecting globe, r = 8 cm = 0.08 m.

    f = \frac{r}{2} = \frac{0.08}{2} = 0.04 m

    1. The image distance, v, can be determined by applying mirror formula:

    \frac{1}{f} = \frac{1}{u} + \frac{1}{v}

    \frac{1}{0.04} = \frac{1}{0.75} + \frac{1}{v}

    \frac{4}{100} – \frac{75}{100} = \frac{1}{v}

    \frac{1}{v} = \frac{4 - 75}{100}

      = – \frac{71}{100}

    ⇒ v = –\frac{100}{71}

          = – 1.41 m

    The image of the person is 1.41 m, virtual and formed at the back of the surface of the globe.

    2.  \frac{image distance}{object distance} = \frac{image height}{object height}

      \frac{1.41}{0.75} = \frac{v}{1.8}

    v = \frac{2.538}{0.75}

      = 3.384

    v = 3.38 m

    The person’s image is 3.38 m tall.

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )