chapter 29.1

Question 1

is a round, three dimensional object , the surface of which is the same distance from the center in all directions

Answer 1

sphere

Question 2

is an elongated closed curve with two foci

Answer 2

ellipse

Question 3

is earth a perfect sphere

Answer 3

no because the diameter is longer then the height of the earth

Question 4

what are some observations that the earth is round

Answer 4

1. objects fall straight down 2. earth’s shadow is on the moon 3. in every part of the world we see different stars

Question 5

what are two things that affect gravitational forces

Answer 5

the one with the bigger mass if they are the same distance and the one that is closer will have a greater gravitational pull

Question 6

what does the magnetic field do for earth

Answer 6

it keeps us from harmful solar radiation

Question 7

which magnetic pole is in the northern hemisphere

Answer 7

south magnetic pole

Question 8

what degrees is earth axis tillted at

Answer 8

11.7 degrees

Question 9

what is the flipping of the north magnetic pull and south magnetic pole

Answer 9

magnetic reversals

Question 10

how often do magnetic poles occur

Answer 10

200,000 years

Question 11

when was the last one that occured

Answer 11

780,000 years ago

Question 12

what is a magnetosphere

Answer 12

defelects harmful radiation from the sun

Question 13

how are auroras created

Answer 13

electrically charged particles collide with atoms in the atmosphere and emit light

Question 14

what is the scientific name for the northern lights

Answer 14

aurora borealis

Question 15

what is the scientific name for the southern lights

Answer 15

aurora australis

Question 16

when is earth closes to the sun

Answer 16

early January 147 million km

Question 17

when is the sun farthest away from the sun

Answer 17

early July 152 million km