1 Measurement key p. 5

  1. RELATIONSHIP BETWEEN METRIC AND ENGLISH MEASUREMENTS

    Your body weight in kg: 165 lb / 2.2 kg/lb = 75 kg.
    The area of the top of your lab book in inches2: 8.5" x 11.0" = 93.5 in2
    The area of the top of your lab book in cm2: 93.5cm x 6.45cm = 603.2 cm2
    190 °F = 87.8 °C ((190 - 32) * .556)
    3 °C = 37.4 °F ((3 * 1.8) + 32)
    15.5 acres / 2.48 = 6.25 hectares (1 hectare is actually 2.47 acres; 15.5 acres should be = 6.27 hectares)

  2. GRAPHING

    Student heights.

  3. SURFACE AREA/VOLUME p. 6

    Original box: L=9.5 W=8.2 H=2.8 (cm)
    SA = 2(lw+lh+wh) = 2(77.9+26.6+23.0) = 2(127.5) = 255 cm2
    V = lwh = 218.12 cm3
    SA/V = 1.17

    Height doubled:
    SA = 2(77.9 + 53.2 + 46) = 2(177.1) = 354.2
    V = 436.24
    SA/V = .81

    Length doubled:
    SA = 2(155.8 + 53.2 + 23.0) = 2(232.0) = 463.0
    V = 436.24
    SA/V = 1.06

    Questions

    1. How did the SA/V change when it grew to twice its original height?
      SA/V decreased

    2. How did the SA/V change when it grew to twice its original length?
      SA/V decreased, but not as much

    3. Imagine the box as being a cell. How can the SA/V be used to explain limits to cell size?
      As cells get bigger, SA/V get smaller, so cells need to be small.

      How can the SA/V of a large cell be maximized?
      Divide one large cell into several smaller cells.

  4. MASS AND VOLUME RELATIONSHIP OF WATER

    Mass of 100ml of water and beaker: 233 g
    Mass of dry beaker: 134 g
    Mass of water: 233 g - 134 g = 99 g
    Volume (cm3) of water (estimate from πr2h): should be about 100 cm3. (1 g of water has a volume of 1 ml (1 cm3) at room temperature.)

    Question p. 7

    1. How did the mass measurement in g and volume measurements in ml and also in cm3 compare to one another?
      100 g water should be 100 ml (cm3) at 4°C

  5. HEAT MEASUREMENT

    Graph of temperature changes over time.

    Be sure to correctly label the axes:
    X(Independent variable) axis: time (min)
    Y(Dependent variable) axis: temperature (°C)

    Temperature should increase over time with warm water

    Temperature should decrease over time with cold water

    Question p. 8
    Did the body temperatures among members of the class vary? Can you provide a reason for the observed outcome?
    Probably not. Humans are homeothermic - body temperature stay around 98.6 °F (37 °C).


Lab notes made Jun 19, 2010 by Peter Chen