show that when an object is very far from a mirror compared with its focal lengt

Question

show that when an object is very far from a mirror compared with its focal length is always formed at the focal point of the miror in less than 500 words and 3800 characters including spaces.

for which type of mirro will the image be erect, and which type will it be inverted?
choices
a) for a convex mirror the image is inverted
B) for a convex mirror rhw image is inverted
C) for a convex mirror the image is erect
D) For a concave mirror the image is erect
answer a and d , a and b , B and C, B and D, or answer not displayed

Explanation / Answer

Part A:

Using the mirror equation, 1/do + 1/di = 1/f , taking the limit of the distance of the object we see as do approaches infinity, 1/do approaches 0 therefore di=f.

Part B:

Using the equation for lateral magnification, m = hi/ho= - di/do we can rearrange to hi= - diho/do. From this equation we can see that when the image distance is positive the image height is negative. Now, remembering that concave mirror make light rays converge, meaning that the image is formed at positive disantances on the principal axis, this tells us that the image height would be negative meaning inverted for a concave mirror and the oppisite for convex since it makes light rays diverge.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

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