Question

Part A.       Cooling Curve

SAFETY NOTE:       Be sure the thermometer will read up to 212 ^oF or 100 ^oC. Otherwise, the thermometer may shatter or break when you place it in the hot water.

1.            Bring 2 cups of water to a boil (make sure it is a “rolling boil” where you can see bubbles)

3.            Allow water to boil for 3 minutes and the record the temperature as “Time 0”

4.            Measure and record the temperature of the water (remember to use ^oC)

5.            Remove the pot from the heat

6.            Measure and Record the temperature of the cooling water

a)            every minute for the first 5 minutes THEN

b)            every 5 minutes after that until there is no change in the temperature of the water (this could take up to 125 min, if it at that point it has not reached room temperature – stop).

7.            Plot the data as a line graph. Temperature is the “Y axis” and time is the “X axis”.

                RAW DATA CHART

Time	Temperature (oC)	Time	Temperature (oC)	Time	Temperature (oC)
0		30		80
1		35		85
2		40		90
3		45		95
4		50		100
5		55		105
10		60		110
15		65		115
20		70		120
25		75		125

                Conclusion Questions:

a)            Define what a linear relationship is.

b)            Is the relationship linear? – Why or Why not?

c)            Can you predict what the temperature will be at 15 minutes based on the graph? Why or Why not?

d)            What will be the final water temper? Why?

Part B.   Mass of Pennies

1.            Collect 25 random pennies

2.            place 5 pennies on the scale, weigh and record the raw data

3.            place 5 more pennies (10 total) on the scale, weigh and record the data

4.            place 5 more pennies (15 total) on the scale, weigh and record the data

5.            place 5 more pennies (20 total) on the scale, weigh and record the data

6.            place 5 more pennies (25 total) on the scale, weigh and record the data

7.            Plot the data as a line graph. Temperature is the “Y axis” and time is the “X axis”.

Raw Data

Pennies (#)	Mass (g)
5
10
15
20
25

Conclusion Questions:

1. Is the relation linear (is the line a straight line)?
2. If you weighed 90 objects what would you predict the mass to be? Why?

Part C. Mass of Different Coins

1.            Obtain 1 of the following: Penny, nickel, dime and quarter

2.            Weigh each coin individually and record the mass

Metal	Mass (g)
penny
nickel
dime
quarter

3.            Plot the data as a bar graph. (“Y axis” = mass; “X axis = type of coin)

Conclusion Questions:

1)            list three examples of when a bar graph would be the appropriate type of graph to choose.

Part D. Percent of the whole

1.            obtain a small package of M&Ms or Skittles.

2.            Separate the candies by color and fill in the raw data chart.

Color	Number in Package	PERCENTAGE
Red
Blue
Green
Yellow
Brown

Calculations

1)            determine the percentage of the total for each color.

                -determine the total number of candies

                -take the number of red candies , divide it by the total and multiply by 100%

               

For example – if there is a total of 50 candies and 10 of them are red –

                                                10/50   x 100%   =   20%

Organized Data:                                Plot the data using a PIE CHART.

Conclusion Questions:

1)            Give three other examples of when a pie chart would be the appropriate graph t use.

Answer 1

Part A

d) The final temperature of the water will be the room temperature as the water attains thermal equilibrium with its surroundings.

Part B

a) Yes, the relation will be linear as each penny has the same weight. As we increase the number of pennies, the total weight increases in linear proportion. Say, one penny weighs 'z' units, 5 pennies will weigh 5z units.

b) As you can observe from the data, the plot will be a straight line of the form y=mx where m, the slope, is equal to the mass of a single penny. Therefore, 90 pennies will weigh 90z with the definition of z as given in a).

Part C

3.1) Bar graphs are used when the 'numbers'/property associated with different quantities is to be compared.

For instance, as in the question, bar graphs can be used to compare masses of coins of the different denominations - penny, nickel, dime and quarter. Bar graphs can also be used to compare populations of different cities, water levels of different rivers, etc.

Part D

1) Pie charts are useful to display the relative contributions of things, say the color of candy, as in the question. Pie charts can also be used to know what commodities the largest portion of the consumers needs or buy in a market or to compare the income from tourist spots in a nation.