Question

Which best describes the image of a concave mirror when

Answer 1

Answer:

when the object goes from the focal length to twice the focal length the image goes from infinity to twice the focal length, this image is real and inverted

Explanation:

Let's use the constructor equation to describe the image of a concave mirror

    1 / f = 1 / p + 1q

where f is the focal length, p and q the distance to the object and the image, respectively

     1 /q = 1/f - 1/p

tell us that the image is between the focal and twice the focal, let's calculate the position of the image

for both ends

case 1, distance to the object       p = f

     

       1 / q = 1 / f -1 / f

       1 / q = 0

       q = ∞

    the image is in infinity

case2, distance to object p = 2f

     1 / q = 1 / f - 1 / 2f

     1 / q = 1 / 2f

     q = 2f

the image is twice the focal length, the object and the image are at the same point

therefore the image when the object goes from the focal length to twice the focal length the image goes from infinity to twice the focal length, this image is real and inverted