ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: squance on January 25, 2008, 11:48:18 am

Title: Apparent Depths
Post by: squance on January 25, 2008, 11:48:18 am

cAN someone please give me a clear explanation of what apparent depth is in relation to physics and how a bent straw in water works (without giving weblinks because they are just crap)

Title: Re: Apparent Depths
Post by: midas_touch on January 25, 2008, 12:56:57 pm

Apparent depth arises due to the difference in refractive indices of the water and the air above it (water is about 1.33 whilst air is close to 1.00). Its a fact that light bends as it travels between two mediums with different refractive indices since its velocity is dependant on the refractive index (speed of light is 3E8 m/s ONLY in a vacuum). Our eyes however do not detect this bending, but assume that the light wasnt bent at the air-water boundary. Since its going from a medium of higher to lower refractive index, the light is bent outwards as it crosses this boundary, and so we underestimate the depth of objects submerged in water looking from above.

*Waits for Coblin to correct me*

Title: Re: Apparent Depths
Post by: Mao on January 25, 2008, 02:37:48 pm

apparent depth:
(http://obsolete-chaos.wikispaces.com/space/showimage/apparent_depth.gif)


Bend Straw
(http://obsolete-chaos.wikispaces.com/space/showimage/bent_straw.gif)