LECTURE 27

Put these in order from highest pressure to lowest pressure: Air pressure inside of a balloon; air pressure inside beach ball; normal atmospheric air pressure A.  B.  C.  D.  E. 

Atmosphere > Beach Ball > Balloon Balloon > Beach Ball > Atmosphere Balloon highest > Atmosphere & Beach Ball the same, Atmosphere highest > Beach Ball & Balloon the same All the same

Challenge: Draw a force diagram that explains WHY the pressure is greater on the inside of the balloon. Recall: Pressure = Force / Area   Hint: Are the air molecules the only entity imparting a force?  

Chapter 10 Problem # 8 The temperature difference between the inside and the outside of a home on a cold winter day is 57.0°F. Express this difference on (a) the Celsius scale and (b) the Kelvin scale. What is the KEY word here?

Chapter 10 Problem # 8 The temperature difference between the inside and the outside of a home on a cold winter day is 57.0°F. Express this difference on (a) the Celsius scale and (b) the Kelvin scale.

Today  

Ideal Gas Law   Pressure   Temperature   Volume

Internal energy   Work and Heat  

Thursday (Last class!) Go over homework   Finish anything we don’t today   Do a fun and educational activity   Evaluations  

Review Session Tuesday, December 11th (dead day)   9-10:15 (normal class time)   In this room   Supply sort of handout or organizational  

Temperature Temperature Scale

lowest

Water melts

Water boils

Fahrenheit

-460

32

212

Celsius

-273

0

100

Kelvin

0

273

373

Space is cold! (~2.7K)

Volume 1 meter3 = ? cm3 A.  B.  C.  D.  E. 

100 1,000 10,000 100,000 1,000,000

Volume 1 meter3 = ? cm3 A.  100 B.  1,000 C.  10,000 D.  100,000 E.  1,000,000

Pressure   The  force  exerted  by  a  fluid  on  a  submerged  object   at  any  point  is  perpendicular  to  the  surface  of  the   object     The  average  pressure  P  is  the  force  divided  by  the   area    

Sec