A lens with a power of -3.5 D indicates a concave lens. To find the focal length, we can use the relationship between power (P) and focal length (f), where P = 1/f. Therefore, the focal length would be -0.29 meters.
If an optician prescribes a lens with a power of -3.5 D, what can you infer about the nature of the lens, and what is its focal length?
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If an optician prescribes a lens with a power of -3.5 D, the nature of the lens can be inferred as a concave lens. The negative power indicates a diverging lens. The focal length (f) can be determined using the formula: f = 1/P, where P is the power of the lens. In this case, f = 1/(-3.5), giving a focal length of approximately -0.29 meters or 29 cm. The negative focal length confirms the diverging nature of the lens, commonly associated with concave lenses used for correcting conditions like myopia (nearsightedness).