Asteroids

The total mass of all the asteroids is less than that of the Moon.

rocky objects with round or irregular shapes

lie in a belt between Mars and Jupiter

Large balls of frozen ice and rock that areonly visible whenthey are close tothe sun

Pebble-sized particles that enter Earth’s atmosphere and burn up leaving a streak of light across the sky

My Very Educated Mother Just Served Us Nine Pies

Draw a line across the table between the terrestrial and jovian planets and label.

Which are more dense?Jovian or terrestrial

Which have more moons ?Jovian or terrestrial

Which have longer periods of revolution?Jovian or terrestrial

Which are larger in size on average ?Jovian or terrestrial

Which planet has the longest day?

Which planet has the longest year?

eccentricity website

Which planet has the least perfectly circular orbit?

Which planet has the most perfectly circular orbit?

Ms. WareEarth Science10/5/09

W.O.T.D.: Eccentricity: is a measure of how an orbit Deviates from circular. A perfectly circular orbit has an eccentricity of zero; higher numbers indicate more elliptical orbits

Do now: If a planet has a mostly oval orbit,Where do you think the planet wouldbe fastest? Why?

A

B

C

D

Sun

Calculate the eccentricity of the ellipse below:

Formula: eccentricity = distance between foci length of major axis

length of major axis

When furthestfrom Sun

When closestto Sun

eccentricity website

Area A=

Area B=

Area C

Explain the difference between the geo- and helio-centric

models of the solar system.

Earth-centered

Sun-centered

Introduction to planet project….

RATIOS and PROPORTIONS REVIEW

By: Teachers who care!

RATIOS & PROPORTIONS

• A ratio is a comparison of two numbers by division.

• To write ratios, use the word to, a colon, or a fraction bar.

EXAMPLE #1: John read 3 books in 4 days. Write the ratio of books to days.

Words: 3 to 4 Colon: 3:4 Fraction: 3/4

RATIOS & PROPORTIONS

• A proportion is a statement that two ratios are equal.

EXAMPLE#2: Is a proportion?15

6

5

2

Find the cross products.

65152 30 = 30 TRUEIf TRUE, the

statement is a proportion.

RATIOS & PROPORTIONS

EXAMPLE#3: Is a proportion?5

3

7

4

Find the cross products. 3754

20 = 21 FALSEIf FALSE, the

statement is NOT a proportion.

RATIOS & PROPORTIONS

EXAMPLE#4: Solve the proportion:10

4

5

Find the cross products. 4510 x

2010 x10 10

2x

Divide both sides by 10.

RATIOS & PROPORTIONS

There are 5 boys and 6 girls in Grant School.

1. What is the ratio of girls to boys using a fraction?5

6

2. What is the ratio of girls to children in Grant School (use a colon)? 6:11

3. What is the ratio of boys to children in Grant School (use words)?

5 to 11

RATIOS & PROPORTIONS

Are the following proportions?

7

3

9

4

20

9

9

4

27

12

9

4

18

8

9

4

3974 2728

FALSE – Not a proportion

99204 8180

FALSE – Not a proportion

129274 108108

TRUE – this is a proportion

89184 7272

TRUE – this is a proportion

RATIOS & PROPORTIONS

Find the missing numbers to make the following proportions.

21

93

9213 x

x963

x79 9

10

5

4

5410 x2010 x

10 10

2x

9

12

3

4

1

941 x36x

If John was 5 ft tall, and Jenny was 6 feet tall how would you

make miniature but proportional copies of them…

5ft= 10 inches 6ft = ??

HINT FOR PROJECT!!!!

SCALE DRAWINGS

• A scale drawing is a drawing of an object with dimensions proportional to those of the actual object. To find lengths from scale drawings, set up and solve proportions.

SCALE DRAWINGS USING PROPORTIONS

EXAMPLE#1: ¼ in = 5 ft is a scale for a rock band’s concert stage.

A. The scale length of the drum stand is 1 in. What is the actual length of the drum stand?

)(

)(

)(

)(

actualobject

drawingobject

ftactual

indrawing

x

1

5

25.

Cross multiply. 1525. x525. x

.25 .2520x

Divide by .25

SCALE DRAWINGS USING PROPORTIONS

EXAMPLE#2: ¼ in = 5 ft is a scale for a rock band’s concert stage.

B. The actual length of the stage is 60 ft. What is the scale length of the stage?

)(

)(

)(

)(

actualobject

drawingobject

ftactual

indrawing

605

25. x

Cross multiply. x 56025.x515

5 5x3

Divide by 5

SCALE DRAWINGS USING PROPORTIONS

Given a scale of ½ in = 4 ft, find the actual length for each scale length given.

x

75.2

4

5.

75.245. x115. x

.5 .5

ftx 22

in4

32 in5

x

5

4

5.

545. x205. x

.5 .5

ftx 40