From 9f63c565550048cc059830fc752bd7f53dc3737a Mon Sep 17 00:00:00 2001 From: Claude Meny Date: Wed, 3 Feb 2021 15:41:47 +0100 Subject: [PATCH] Update annex.fr.md --- .../30.beyond/annex.fr.md | 21 ++++++++++--------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/instructions-for-levels/30.beyond/annex.fr.md b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/instructions-for-levels/30.beyond/annex.fr.md index 9d400e0f8..47f091da3 100644 --- a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/instructions-for-levels/30.beyond/annex.fr.md +++ b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/instructions-for-levels/30.beyond/annex.fr.md @@ -172,7 +172,7 @@ Sont proposées les catégories suivantes, mais à débattre, toutes les idées ! What is the optical system giving the image of the painting? ! !
-! * The optical system is composed of two spherical refracting surfaces, centered on the same optical axis. +! * The optical system is composed of two spherical refracting surfaces, centered on the same optical axis.
!
! !
@@ -187,11 +187,13 @@ Sont proposées les catégories suivantes, mais à débattre, toutes les idées !* The first spherical refracting surface ! $`DS1`$ encountered by the light has ! the follwing characteristics :
-! $`\overline{S_1C_1}=+|R|=+5\;cm`$ , $`n_{ini}=1`$ and $`n_{fin}=1.5`$ +! $`\overline{S_1C_1}=+|R|=+5\;cm`$ , +! $`n_{ini}=1`$ and $`n_{fin}=1.5`$
!
-! * The second spherical refracting surface $DS2$ -! encountered by the light has the follwing characteristics :
-! $`\overline{S_2C_2}=-|R|=-5\;cm`$ , $`n_{ini}=1.5`$ and $`n_{fin}=1`$ +! * The second spherical refracting surface +! $DS2$ encountered by the light has the follwing characteristics :
+! $`\overline{S_2C_2}=-|R|=-5\;cm`$ , +! $`n_{ini}=1.5`$ and $`n_{fin}=1`$ ! ! * Algebraic distance between $DS1$ and $DS2$ is : $`\overline{S_1S_2}=+10\;cm`$ ! @@ -458,24 +460,23 @@ Sont proposées les catégories suivantes, mais à débattre, toutes les idées ! ! What is the apparent magnification of the cathedral ? ! -!
-! * "apparent magnification" = "angular magnification" = "magnifying power". +! * apparent magnification = angular magnification = magnifying power. ! ! * As calculated previously, standing 400 metres from the cathedral, the 90 m heigh ! cathedral sustends the apparent angles of $`\alpha=arctan\left(\dfrac{90}{400}\right)=0.221\;rad=12.7°`$ -! at your eye. +! at your eye.
!
! * The image of the cathedral is 1.7 cm heigth and is located between the lens ! (from its vertex $`S2`$) and your eyes and at 2.5cm from the lens. If your eye is ! 20cm away from the lens, so the distance eye-image is 17.5 cm (we use no algebraic values). ! Thus the image of the catedral subtends the apparent angle -! $`\alpha'=arctan\left(\dfrac{1.7}{17.5}\right)=0.097\;rad=5.6°`$ at your eye. +! $`\alpha'=arctan\left(\dfrac{1.7}{17.5}\right)=0.097\;rad=5.6°`$ at your eye.
!
! * The apparent magnification $`M_A`$ of the cathedral throught the lensball for my ! eye in that position is
! $`M_A=\dfrac{\alpha'}{\alpha}=\dfrac{0.097}{0.221}=0.44`$.

! Taking into account that the image is reversed, the algebraic value of the apparent -! magnification is $`\overline{M_A}=-0.44`$. +! magnification is $`\overline{M_A}=-0.44`$.
!
! * You could obtained directly this algebraic value of $`M_A`$ by considering algebraic ! lengthes and angles values in the calculations :