Question

procedure g: apparent motion of the sun in bh
many times you have observed the sun rising in the morning, moving across the sky during the day, and setting in the evening. this is only an apparent motion. we have already learned that the real motion of earths rotation is responsible for this apparent motion of the sun.
step 1 directions:

1. obtain a piece of cardboard, a compass, a red - mark marker, and a plastic dome.
2. go outside with the class. orient your cardboard correctly, meaning you should use your compass to line up the north arrow on your cardboard with the direction shown as north on your compass.
3. move your red - mark marker around above the plastic dome until the tip of the marker lines up with the center of the circle on the cardboard (as seen in diagram 1 below). mark this point and label the date and time.

step 2 directions: the point marked on the dome by your group is now connected to other points marked on the same day. this creates an apparent path for the sun across our sky in burn hills. answer the following questions based on your dome.

1. what is the shape of the apparent path of the sun across the sky?
2. according to the plastic dome and your data, did the sun rise directly in the east and set exactly in the west on the fall equinox?
3. according to the plastic dome and your data, was the sun directly overhead at noon? why or why not?
4. according to your observations, what is the approximate angular distance (angle) in degrees the sun moves in one hour?

at the rate you calculated in #2, how many hours would it take the sun to travel 360°?

1. what actually causes the apparent motion of the sun (described in questions #4 - #5)?

Explanation:

Step1: Recall sun - path shape

The apparent path of the sun across the sky is an arc. This is because of the Earth's spherical shape and its rotation.

Step2: Analyze equinox sunrise - sunset

On the fall equinox, the sun rises directly in the east and sets exactly in the west. This is a characteristic of equinoxes when the tilt of the Earth's axis is not causing a significant difference in the length of day and night.

Step3: Consider sun's position at noon

The sun is not directly overhead at noon. This is because most locations on Earth (except those between the Tropic of Cancer and the Tropic of Capricorn) do not experience the sun being directly above at noon.

Step4: Calculate angular distance per hour

The sun moves approximately 15 degrees in one hour. This is because the Earth rotates 360 degrees in 24 hours, so $\frac{360}{24}=15$ degrees per hour.

Step5: Determine time to travel 360 degrees

If the sun moves 15 degrees per hour, to travel 360 degrees, it would take $\frac{360}{15}=24$ hours. This is consistent with the Earth's 24 - hour rotation period.

Step6: Identify cause of apparent motion

The apparent motion of the sun is caused by the Earth's rotation on its axis. As the Earth rotates, it gives the impression that the sun is moving across the sky.

Answer:

1. Arc
2. Yes
3. No, because most locations are not between the Tropic of Cancer and the Tropic of Capricorn.
4. 15 degrees
5. 24 hours
6. The Earth's rotation on its axis.