Chapter 29.1

Question 1

a round three-dimensional object

Answer 1

sphere

Question 2

an elongated, closed curve with two foci

Answer 2

ellipse

Question 3

is earth a perfect sphere

Answer 3

no because the diameter is a little longer then the height

Question 4

what are some pieces of ancient observations that proves that the earth is a sphere

Answer 4

objects fall straight down, the shadow of earth on the moon, and in every part of the world we see different stars

Question 5

what are two things that affect gravitational forces

Answer 5

mass and distance

Question 6

which diameter on earth is longer

Answer 6

equator

Question 7

what does the magnetic field do for earth

Answer 7

protects earth from harmful radiation from the sun

Question 8

which magnetic pole is in the northern hemisphere

Answer 8

south magnetic pole

Question 9

can these magnetic poles flip

Answer 9

yes

Question 10

what degrees is earths axis tilted at

Answer 10

11.7 degrees

Question 11

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

Answer 11

magnetic reversal

Question 12

how often do magnetic reversals occur

Answer 12

200,000 years

Question 13

when was the last magnetic reversal occured

Answer 13

780,000 years

Question 14

what is a magnetosphere

Answer 14

deflects harmful radiation from the sun

Question 15

how the auroras created

Answer 15

electrically charged particles collide with atoms in the atmosphere

Question 16

what is the scientific name of the northern lights

Answer 16

aurora borealis

Question 17

what is the scientific name for the southern lights

Answer 17

aurora australis

Question 18

when is earth closest to the sun

Answer 18

early January (147 million km away)

Question 19

when is earth farthest from the sun

Answer 19

early July (152 million km away)