Physics 106P: Lecture 1 Notes

1
Physics 123
Try to explain why some things might feel colder
than other things even though they are really at
the same temperature A) The material, such as
metal, is not able to hold the warmth as easily.
It has a cold surface because it does not absorb
heat, such as wood might. B) If something is a
better conductor of heat it would feel colder
because it takes the heat out of your body more
quickly and more efficiently than something that
isn't a conductor of heat. C) It depends on how
well the material stores heat. D) Some things
might feel colder because of the materials they
are made of. For example, while atoms vibrate
slower as they get colder, certain materials,
while the same temperature, might have a natural
tendency to vibrate slower or faster. For
example, metal atoms may vibrate, naturally
slower than wood atoms. E) Some materials were
able to absorb the cool air while it remained
only on the surface of others.
2

• Suppose you have a ice at 0o C covering your
  sidewalk. You toss some salt onto this ice and
  you notice that after a while the has melted into
  slush. What is the temperature T of this slush?
• T 0o
• T lt 0o
• T gt 0o

3

• How much energy does a person need every day to
  walk talk think live?
• About the same as a light bulb 
• Much less than a light bulb
• Much more than a light bulb
•  

4
I vaguely remember my freshmen high school
physics teacher creating a vacuum and boiling ice
water, but I can't remember why that worked! 
5

•   Suppose you put a pot of cold water on the
  stove, placed a thermometer in it, and turned on
  the burner. Which of the following statements
  about the reading on the thermometer as a
  function of time is true
•   A) The temperature of the water would climb
  steadily to 100 degrees C. At this point the
  water would start to boil, and the temperature of
  the boiling water would keep increasing steadily
  past 100 degrees .  
• B) The temperature of the water would climb
  steadily to 100 degrees C. At this point the
  water would start to boil, which would cause the
  temperature of the water to decrease below 100
  degrees C.  
• C) The temperature of the water would climb
  steadily to 100 degrees C. At this point the
  water would start to boil, and the temperature of
  the boiling water would stay at 100 degrees C.

6

• Albert has a half cup of coffee that is 80
  degrees C. Isaac has half a cup of coffee that is
  50 degrees C. If they mixed all of their coffee
  together, what would the temperature of the
  mixture be?
• A) 30 degrees C  
• B) 50 degrees C  
• C) 65 degrees C  
• D) 80 degrees C  
• E) 130 degrees C

7
Why is hair more static-y in the winter?