Author Question: The book shows a photograph of a human face, taken at shorter and shorter camera exposure times. ... (Read 78 times)

cartlidgeashley · **on:** Jul 29, 2018

The book shows a photograph of a human face, taken at shorter and shorter camera exposure times. What is observed at the shortest exposure times, and what does this observation demonstrate about the nature of light?

A) We observe a very dim but complete image of the face, showing that light is made of waves that have smaller amplitude as the light is reduced.
B) We observe light and dark lines due to interference, showing that light is a wave.
C) Individual white dots are distributed all over the photographic plate, showing that light is made of waves.
D) We observe individual white dots at the center of the photograph, showing that the camera tends to focus individual photons at this point.
E) Individual white dots were distributed randomly over the photographic plate, showing that light interacts with the screen in tiny bundles.

Question 2

The rms speed of a certain sample of carbon dioxide molecules, with a molecular weight of 44.0 g/mole, is 396 m/s. What is the rms speed of water vapor molecules, with a molecular weight of 18.0 g/mol, at the same temperature as the carbon dioxide?

A) 253 m/s
B) 387 m/s
C) 421 m/s
D) 506 m/s
E) 619 m/s