just need some help not sure what formula to use? A lamp which is 9.5 cm tall is

Question

just need some help not sure what formula to use?

A lamp which is 9.5 cm tall is 137.7 cm in front of a converging lens which has a focal length of 76.5 cm. (a) What is the image distance for this lamp and lens combination (include sign if negative)? cm (b) If a screen is placed at the image location found in (a), what will be observed on the screen? a clear, upright, virtual image is visible no image is visible on the screen a clear, upright, real image is visible a clear, inverted, real image is visible a clear, inverted, virtual image is visible (c) If the screen is moved slightly farther from the lens than the distance found in (a), what will be observed on the screen? a clear image slightly smaller than the original image is visible a fuzzy image is visible no image is visible on the screen a clear image slightly larger than the original image is visible

Explanation / Answer

Part A)

Apply the lens equation

1/f= 1/p + 1/q

1/47.5 = 1/185.3 +1/q

q = 63.9 cm  

Part B)

We can find the magnification, and it will show us the following

M = -q/p = -63.9/185.3

M = -.345

Using the fact that the image distance q is positive, and the magnification is negative, that tells us that the image is real and inverted.

Part C)

If you move the screen away from the point of focus for the image, the image begins to become fuzzy. The further away, the fuzzier until its not visible at all as an image.

Related Questions

Navigate

• Browse (All)
• Browse J
• Subjects

---

---

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