An object is placed 12 cm in front of a concave mirror whose focal length is 16

Question

An object is placed 12 cm in front of a concave mirror whose focal length is 16 cm. The object is 3.9 cm tall. Determine (a) the location of the image, taking a real image as a positive value and a virtual image as a negative value. (b) Determine the height of the image, where an upright image will have a positive height and an inverted image will have a negative height.

An object is placed 12 cm in front of a concave mirror whose focal length is 16 cm. The object is 3.9 cm tall. Determine (a) the location of the image, taking a real image as a positive value and a virtual image as a negative value. (b) Determine the height of the image, where an upright image will have a positive height and an inverted image will have a negative height.

Explanation / Answer

For a mirror
1/f = 1/v + 1/u
here u = 12 cm ; f = 16 cm
1/22 = 1/v + 1/11
1/v = 1/16 - 1/12
1/v = -1/48
v = -48 cm
Therefore the image is virtual and is at distance 48cm from the concave mirror.
now magnification (m) = -v/u
also m = Hi/Ho where Hi is Image height and Ho is object height
therefore
-(-48)/12 = Hi/3.9
Hi = 15.6cm

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.