chapter 29.1

Question 1

sphere

Answer 1

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

Question 2

elipse

Answer 2

is a elongated, closed curve with two foci

Question 3

is earth a perfect sphere

Answer 3

no, because the diameter is longer

Question 4

what are some pieces to ancient observations to prove that earth is a sphere

Answer 4

objects fall straight down, earths shadow on the moon, and in every part of the world we see different stars if we were flat we would see the same stars

Question 5

what are two thing that effects gravitational forces

Answer 5

the one with bigger mass with an equal distance, and the one that is closest to the object

Question 6

which diameter of the earth is longer

Answer 6

the equator

Question 7

what does the magnetic field do for earth

Answer 7

protects us from harmful radiation for 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 reversals

Question 12

how often do magnetic reversals occur

Answer 12

every 200,000

Question 13

when was the last magnetic reversal

Answer 13

780,000 years ago

Question 14

what is a magnetosphere

Answer 14

deflects harmful radiation from the sun

Question 15

how are the auroras created

Answer 15

when electrically charged particals collide with atoms in the atmosphere

Question 16

what is the name of the northern light and southern light

Answer 16

the northern lights name is aurora borealis, and the southern lights are aurora australis

Question 17

when is earth closest to the sun

Answer 17

early January about (147 million kilometres)

Question 18

when is earth furthest from the sun

Answer 18

early july (152 million kilometres)