rotating head periscopes why u-boat captains have to spin in circles these periscopes are resource...
TRANSCRIPT
Rotating Head PeriscopesWhy U-boat Captains Have To Spin In
Circles
These periscopes are resource material to support parts of
STAO’s ScienceWorks Grade 10 Optics
The following are excerpts fromL4 The Laws of Reflection (Slides 21-35 of58)
andL5 Putting Things Together (Slides 1-14 of54)
Safety note; Extra tape should be placed at the corners to cushion some of the sharp edges on the plastic mirrors.
PeriscopesWhy U-boat Captains Have To Spin In Circles
1) Use the laws of reflection to show how the Eye/Brain sees the top and bottom of a candle in a periscope?
PeriscopesWhy U-boat Captains Have To Spin In Circles
Roughly parallel rays from the top and bottom of the candle move towards the top mirror
PeriscopesWhy U-boat Captains Have To Spin In Circles
Angle of Incidence = Angle of Reflection (i = r ) and the rays move towards the bottom mirror
PeriscopesWhy U-boat Captains Have To Spin In Circles
Angle of Incidence = Angle of Reflection (i = r ) and the rays move towards the Eye/Brain mirrorNote: This does not predict the Image’s location.
PeriscopesWhy U-boat Captains Have To Spin In Circles
The candle’s image appears erect.
2) Use the laws of reflection to show how the Eye/Brain sees the top and bottom of a candle if the top mirror is be rotated to face backwards?
PeriscopesWhy U-boat Captains Have To Spin In Circles
PeriscopesWhy U-boat Captains Have To Spin In Circles
Roughly parallel rays from the top and bottom of the candle move towards the top mirror
PeriscopesWhy U-boat Captains Have To Spin In Circles
Angle of Incidence = Angle of Reflection (i = r ) and the rays move towards the bottom mirror
PeriscopesWhy U-boat Captains Have To Spin In Circles
Angle of Incidence = Angle of Reflection (i = r ) and the rays move towards the Eye/Brain mirrorNote: This does not predict the Image’s location.
PeriscopesWhy U-boat Captains Have To Spin In Circles
The candle’s image appears inverted.
3) Use the laws of reflection to show how the Eye/Brain sees the top and bottom of a candle if the top mirror is rotated to face sideways?
PeriscopesWhy U-boat Captains Have To Spin In Circles
The candle appears to be sideways.
PeriscopesWhy U-boat Captains Have To Spin In Circles
PeriscopesWhy U-boat Captains Have To Spin In Circles
The man of science has learned to believe in justification, not by faith, but by verification.— Thomas Henry Huxley
Seeing Things
Putting Things Together
Periscopes, Hinged Mirrored & Kaleidoscopes
1) Where exactly are the Images in a periscope AND how do light rays reach the Eye/Brain from the Object?
Periscopes
Find the first image (Image 1) in the top mirror using equal perpendicular distances . You have to extend the mirror to locate the Image.
Images can act like Objects. Find the second image in the bottom mirror the same way. But this time use Image 1 as the new Object
The Eye/Brain sees the second image in the bottom mirror as usual. Rays of light appear to come straight from it.
Light rays cannot travel through the opaque bottom mirror. They must have come from the Object (Image 1) and reflected off the mirror.
The light rays cannot travel through the opaque top mirror. They must have come from the real Object and reflected off the top mirror.
Your TurnAttempt the Questions on
L5 Putting Things Together Student Notes
Periscopes
Periscopes2) Where exactly are the Images in a reversed
periscope AND how do light rays reach the Eye/Brain?
Find the first image (Image 1) in the top mirror using equal perpendicular distances . You have to extend the mirror to locate the Image.
Images can act like Objects. Find the second image in the bottom mirror the same way. But this time use Image 1 as the new Object
The Eye/Brain sees the second image in the bottom mirror as usual. Rays of light appear to come straight from it.
Light rays cannot travel through the opaque bottom mirror. They must have come from the Object (Image 1) and reflected off the mirror.
The light rays cannot travel through the opaque top mirror. They must have come from the real Object and reflected off the top mirror.