truong2k1

2 năm trước

cho 1 vật AB dạng hình mũi tên vuông góc với trục chính, A nằm trên trục chính.Hãnh dựng ảnh của vật qua thấu kính hội tụ.Có tiêu cực f = 12 cm. trong các tình huống sau a)Vật ab cắt kính 24 cm , vật cao 1 cm . tính chiều cao của ảnh b) vật ab cách thấu kính 6 cm c)vật cách kính 16 cm , tính khoảng cách từ ảnh đến thấu kính gửi ảnh cho mình nha

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Trương Tiến Nhật

2 năm trước

a, Vì $d=2f$

$⇒d'=d=24cm$

$h'=h=1cm$

b, Vì $d<f$

$⇒\dfrac{1}{d}-\dfrac{1}{d'}=\dfrac{1}{f}$

$⇔\dfrac{1}{6}-\dfrac{1}{d'}=\dfrac{1}{12}$

$⇔d'=12cm$

c, Vì $d>f$

$⇒$ Ta có: $\dfrac{1}{d}+\dfrac{1}{d'}=\dfrac{1}{f}$

$⇔\dfrac{1}{16}+\dfrac{1}{d'}=\dfrac{1}{12}$

$⇔d'=48cm$

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