DTA Scoring Form

Daytime Astronomy SHADOWS Score Form

Date ____/____/____ Student ______Rater ______

Problem I. (Page 3) Accuracy of results Draw a dot on this map to show where you think Tower C is. Tower C is in Eastern US Tower C is in North Eastern US Tower C is somewhere in between Pennsylvania and Maine

Modeling/reasoning/observation How did you figure out where Tower C is? Matched shadow lengths of towers A and B/ pointed flashlight to Equator Tried different locations for tower C/ inferred location of tower C Matched length of shadow C/considered Latitude (distance from Equator) Matched angle of shadow C/ considered Longitude (East-West direction)

Problem II. (Page 4) Accuracy of results How does the shadow of Tower A look at 10 AM and 3 PM?... Which direction is the shadow moving? 10 AM shadow points to NNW 10 AM shadow is shorter than noon shadow 3 PM shadow points to NE 3 PM shadow is longer than noon shadow Clockwise motion of shadows

Modeling/reasoning/observation How did you figure out what the shadow of Tower A looks like at 10 AM and 3 PM? Earth rotation/ "Sun motion" Sunlight coming from East projects a shadow oriented to West Sunlight coming from West projects a shadow oriented to East Sunlight coming from above us projects a shadow oriented to North Sun shadows are longer in the morning than at noon Morning Sun shadows become shorter and shorter until its noon The shortest Sun shadow is at noon Sun shadows are longer in the afternoon than at noon Afternoon Sun shadows become longer and longer until it gets dark

(Over, please) - 1 - 6/95 Problem III. (Page 5) Accuracy of results What time do you think it is in Seattle when it's noon for Towers A and B? Seattle's time is earlier than noon Seattle's time is later than 8 AM and earlier than noon Seattle's time is 10 or 11 AM

Modeling/reasoning/observation Why? Earth rotates from West to East/ Sun "rises" at East and "sets" at West Western time is earlier than Eastern time Seattle is more Western than Towers A and B

What do Sun shadow and the Earth's motion have to do with time? Sun shadows move as Earth rotates (or Sun moves)

Problem IV. (Page 7) Accuracy of results Draw how a Sun shadow looks at the Southern Hemisphere at 10 AM, Noon, and 3 PM... Which direction is the shadow moving? The three shadows oriented downwards 10 AM shadow points to SSW 10 AM shadow shorter than noon shadow 3 PM shadow points to SE 3 PM shadow longer than noon shadow 3 PM shadow longer than 10 PM shadow 3 PM-noon shadow angle wider than 10-noon shadow angle Counterclockwise motion of shadows

(Page 8) Modeling/reasoning/observation How did you figure out what a Sun shadow looks like at the Southern Hemishphere at 10 AM, Noon, and 3 PM? Sunlight hits the Equator Earth rotates from West to East/ Sun "rises" at East and "sets" at West

Do Sun shadows move and change the same way in the Northern Hemisphere and Southern Hemisphere? Sun shadows point upwards in the Northern Hemisphere and downwards in the Southern Hemisphere Sun shadows move clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere Sun shadows orient symmetrically in Northern Hemisphere and Southern Hemispheres Length of Sun shadows at the same time of the day is the same for both hemispheres

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