Paper Airplanes Make a hypothesis of which airplane

Paper Airplanes • Make a hypothesis of which airplane would fly the best between one made of copier paper and one of construction paper • Why?

Paper Airplanes continued • Group up by color • Make two airplanes per group • Go into the lab, throw each airplane ten times and record the measurements • Plot of a graph the distance on the x axis and the number of throws on the y axis • Which flew the furthest? • Why? – https: //www. youtube. com/watch? v=Qo. Tbg. SSTB 3 E

Paper Airplanes continued • Now, trade which ever airplane flew furthest with another group (of theirs that flew furthest) • Which is best? • What are you basing “best” on? • Consider whether it is: – – Distance Speed Hang-time Appearance, etc. • Why is it important to define “best”?

Properties of Water

Hypothesis • Mixing Hot and Cold Water – https: //www. youtube. com/watch? v=Aas. Kk 3 H Ry. OI

Conclusion • Water density! – Cold water is more dense than warm water – Example: • 68 degree water has a density of 0. 9982 g/cm 3 • 104 degree water has a density of 0. 9922 g/cm 3 – So what about ice?

Properties • Universal solvent – Can dissolve many compounds but… – Is also the property that allows runoff and groundwater infiltration of nutrients – http: //www. physicalgeography. net/fundamentals/8 a. html • High surface tension – Reason water forms droplets on your windshield rather than spread out • Present in nature if all three phases (solid, liquid, gas) • Pure water has a p. H of 7. 0 SU – Rain can have a p. H as low as 2. 3 SU