5.11

5.11 Starter

02 November 2011

16:58

	<<Video - Brownian Motion smoke in air.wmv>>

·         

You're looking at smoke particles in air under a microscope

·         They appear to be jiggling about

·         Why?

 

·         (Don't worry if you can't work this out straight away - Albert Einstein was the bloke who eventually explained what's happening here!)

5.11

28 October 2011

11:10

·         5.11 understand the significance of Brownian motion

	<<Video - Model of Brownian motion.wmv>>

Model 1

·         What does the red puck represent?

·         What do the metal balls represent?

red puck = smoke

metal balls = air molecules

			<<brownian_motion.swf>>

Model 3

·         What do the "smoke" particles look like?

·         Why are they moving?

·         What do the "air" particles look like?

5.11 explained

28 October 2011

11:10

Model 1

·         What does the red puck represent?

o    The large, visible smoke particle

·         What do the metal balls represent?

o    The small, not visible air particles

 

Model 2

·         What do the small red particles represent?

o    The small, not visible air particles

·         What does the large blue particle represent?

o    The large, visible smoke particle

·         What does the view on the left of the screen represent?

o    The view through the microscope lense

·         Why can't you see the red particles in this view?

o    They are too small to see

 

Model 3

·         What do the "smoke" particles look like?

o    They are the 5 large, sand coloured particles

·         Why are they moving?

o    Small, fast moving air particles are colliding with the smoke particles and making them move

·         What do the "air" particles look like?

o    They are the numerous, small, white particles

5.11 Questions

02 November 2011

17:21

1. Draw the path of a smoke particle in air  (3 marks)

you cannot because smoke particles move about randomly depending on when it hits the air particles

2. 

Explain what is meant by Brownian Motion of smoke particles in air and how it provides evidence for air particles  (4 marks)

brownian motion - the movement of small particles as a result of continuous contact with molecules in the same space

3. 

What change would you expect to see in the movement of the smoke particles if the air was cooled down?  Why?  (2 marks)

you would expect them to move slower because as you cool it down the particles move slower thus more collisions are caused

brownian_motion.swf Download this file