Homework SourseA slide projector needs to create a 970 cm high image of a 1
A slide projector needs to create a 97.0 cm high image of a 1.90cm tall slide . The screen is 299 cm from the slide.
A) What focal length does the lens need ? Assume that it is a thin lens. Express your answer with appropriate units
B). How far should you place the lens from the slide? Express your answer with appropriate units
A slide projector needs to create a 97.0 cm high image of a 1.90cm tall slide . The screen is 299 cm from the slide.
A) What focal length does the lens need ? Assume that it is a thin lens. Express your answer with appropriate units
B). How far should you place the lens from the slide? Express your answer with appropriate units
A) What focal length does the lens need ? Assume that it is a thin lens. Express your answer with appropriate units
B). How far should you place the lens from the slide? Express your answer with appropriate units
Solution
h\' = 97 cm, h = 1.90 cm
s + s\' = 299 cm
a) m = h\' / h = 97 / 1.90 = 51.05 cm = s\' / s
s\' = 51.05 s
s + s\' = 299 cm
s + 51.05 s = 299 cm
s = 5.744 cm
s\' = 299 - 5.744 = 293.3 cm
1 / f = 1 / s + 1 / s\' = 1 / 5.744 + 1 / 293.3
f = 5.633 cm
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s = 5.744 cm
