Planisphere Worksheet Use your planisphere to answer the following questions. 1.

2.

Find the following stars and list their constellations: a)

Polaris:

b)

Sirius:

Draw a horizon sketch facing south for 8pm tonight.

a)

Identify a constellation on the horizon from that sketch.

b)

Identify a constellation on the meridian from that sketch.

c)

What constellation is nearest the zenith at 8pm?

3.

Draw a horizon sketch facing south for midnight.

4.

Draw a horizon sketch facing north for 8pm tonight.

5.

Draw a horizon sketch facing north at midnight.

6.

Find the rising times of the following constellations on January 1st and March 1st. Orion: Gemini: Leo: Taurus: Corona Borealis:

Phases The purpose of this exercise is to have you construct a model that accounts for the observations made of the phases of the Moon. At the end, you should be able to explain why phases occur, and deduce which phases would be visible for different situations. Part I: The Phases Draw/fill in the following diagrams of the Moon to show the different phases:

New Moon

Waxing Crescent

First Quarter

Waxing Gibbous

Full Moon

Waning Gibbous

Last Quarter

Waning Crescent

How much time is there between new moon and the next new moon? How much time is there between new moon and full moon? How much time is there between full moon and last quarter?

Part II: The Model Your group should have a Moon ball and a Sun (light bulb). Your head represents Earth. 1. Move the Moon around some, and observe the bright side. Which way does the bright side of the Moon always face?

2. What do you think causes the phases of the Moon? Write a brief explanation.

3.

Position the Moon to get a first quarter moon as seen by people on Earth. Be sure everyone in your group gets to see this. Then sketch the situation below (include the Sun, Moon, and Earth):

4. Position the Moon to get a waxing crescent, and sketch the situation:

5. Position the Moon to get a waxing gibbous moon, and sketch the situation:

6. Position the Moon to get a last quarter moon, and sketch the situation:

7. What causes the phases of the Moon?

8. Make a sketch of the situation for a new moon:

9. If the Moon is in the first quarter phase, in what phase would an astronaut on the Moon observe the Earth?

10. If an astronaut sees a crescent Earth, what would an observer on the Earth see when observing the Moon?

The Pendulum Problem You are the counselor for a ruler in an ancient land. This ruler wants to have a new kind of clock based on a pendulum. Since you are a wise and trusted advisor, you have been asked to design the clock. To make sure you do this well, you decide to experiment and see what affects the period of a pendulum. Question: what affects the period of a pendulum, and how? Specifically, what happens if we change the mass, length, or amplitude? Getting data • Measure the period of a pendulum with different masses on the end (but the same length and amplitude) and record the data in the table below. Be sure to get at least 5 data points from ~10 g to ~200 g. Time 10 complete swings and use the average period. • Measure the period of a pendulum with different lengths (but the same mass and amplitude) and record the data below. Be sure to get at least 5 data points from ~20 cm to ~200 cm. Time 10 complete swings and use the average period. • Measure the period of a pendulum with different amplitudes (but the same mass and length) and record the data below. Be sure to get at least 5 data points from ~10° to ~45°. Time 10 complete swings and use the average period. Analyzing the data • Decide what variable(s) affect the period of a pendulum. • Graph paper and further questions will be provided. Data Trial: Mass Period Length Period Amplitude Period

1

2

3

4

5

6

7

1.

What factor(s) affect the period of the pendulum? How do you know?

2. Fill in the table below, and then graph Period (y) vs. each column (x). Length (cm)

3.

L

L2

Period (s)

What is the relation between the period and the length of a pendulum according to your graphs?