IDS 102 Quiz 1

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IDS 102 Quiz 1

• Jiminy Cricket
• and mixing water

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What do we know about ??J?
Celsius Temperature Jiminy Temperature
Cool night 15 ?C 76 ?J
Hot day 35 ?C 220 ?J
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1a) The Graph (1 pt)

• This is good

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1a) The Graph

• Is this more useful? (Maybe, maybe not)

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1b) Find the equation (2 pts)

• First find the slope
• Key question Whats y? Whats x?

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1b) The equation

• Then find the intercept
• Choose ONE point on your graph
• such as (15? C, 76? J) (whats y? whats x?)

Notice that the intercept is NEGATIVE! We knew
this from the graph.
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1b) The equation

• So the equation is
• (? Jiminy) (7.2)(? Celsius) 32
• Hint write it in a way so that youcant forget
  whats y? whats x?

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1c) Specific temperatures (2 pts)

• In degrees Jiminy, water freezes at
• (7.2)(0 ? Celsius) 32 -32 degrees Jiminy
• In degrees Jiminy, water boils at
• (7.2)(100 ? Celsius) 32 688 degrees Jiminy

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2) Complete the sentence (1 pt)

• When we say that one object is warmer than
  another, what we mean is that the warmer object
  has a higher temperature.
• When a warm object is placed in contact with a
  cold object the warm object gives some heat to
  the cold object.

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3) Mixing water

• a) (2 pts) If only 20 calories changes hands
• The 50 gram water sample (initially at 20?) warms
  up, so we just need to figure out how much
• The 20 gram water sample (initially at 55? C)
  cools down by

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3) Mixing water

• b) (2 pts) Once heat transfer has stopped
• The final temperature will be

You could also solve this by preparing a table.
The table would have to be large enough that a
total of 500 calories could be transferred from
the warm water to the cool water.