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Nutka1998 [239]

2 years ago

14

An object with a height of 4.0 cm is placed 30.0 cm from a lens. The resulting inverted image has a height of 1.5 cm. What is th

e focal length of the lens? A. 15 cm B. 7.5 cm C 17 cm D. 8.2 cm E. 21 cm

1 answer:

jarptica [38.1K]2 years ago

6 0

Answer:

Focal length of the lens is 8.2 cm.

Explanation:

It is given that,

Height of object, h = 4 cm

Object distance, u = -30 cm

Height of the image, h' = -1.5 cm (negative because the image is inverted)

We need to find the focal length of the lens. It can be calculated using lens formula as :

$\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}$

Magnification, $m=\dfrac{v}{u}=\dfrac{h'}{h}$

$\dfrac{v}{-30}=\dfrac{-1.5}{4}$

Image distance, v = 11.25 cm

$\dfrac{1}{11.25}-\dfrac{1}{-30}=\dfrac{1}{f}$

f = 8.18 cm

or f = 8.2 cm

So, the focal length of the lens is 8.2 cm. Hence, this is the required solution.

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Answer:

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Explanation:

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$\text{heat loss } = \frac{T_1 - T_2} { \frac{1}{h_1} + \frac{t_1}{t_2} + R_c + \frac{t_2}{k_2} + \frac{1}{h_2}}$

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$\text {heat loss} = h_1 (T_1 - T_{s1})$

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2 years ago

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2 years ago

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Answer:

Force applied to smaller cross section is

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