Astronomy

Question 1

gravitational field strength equation

Answer 1

weight = mass x gravitational field strength

Question 2

mass

Answer 2

the amount of matter in a substance (kg)

Question 3

weight

Answer 3

a force (N)

Question 4

what does gravitational force cause?

Answer 4

1. the planets to orbit the sun
2. the moon (natural satellite) and artificial satellites to orbit Earth
3. the comets to orbit the sun

Question 5

scale of things in the universe

Answer 5

earth
sun
(billions of) stars
(billions of) galaxy (milky way)
universe

Question 6

the planets

Answer 6

inner planets, small and rocky: mercury, venus, earth, mars
outer planets, large and gaseous: jupiter, saturn, uranus, neptune

Question 7

orbital speed equation

Answer 7

orbital speed = (2 x pi x orbital radius) / time period

Question 8

orbit of a comet, moon and planet

Answer 8

highly elliptical, elliptical, mostly circular

Question 9

how was the moon formed?

Answer 9

formed with some of the crust that was thrown into orbit when a mars-sized planet collided with earth

Question 10

how often does the moon circle around the earth?

Answer 10

once every 27.5 days

Question 11

what are artificial satellites used for?

Answer 11

telecommunications, satellite navigation systems, weather forecasts

Question 12

stationary orbit

Answer 12

circles around the earth the same rate as the earth does so it appears to be stationary (across the equator)

Question 13

what occupies a stationary orbit?

Answer 13

communication satellites

Question 14

polar orbits

Answer 14

passes over the north and south poles and crosses the equator twice per orbit

Question 15

what occupies a polar orbit?

Answer 15

observation and monitoring satellies

Question 16

what are comets consisted of?

Answer 16

ice and dust