Question

1. The 6h 20 min between low and high tide is caused by what?
2. The 7 days between very large to mild CHANGES in tides is caused by what?
3. We see very large tide changes when the moon is in what two phases?              We see mild tide changes when the moon is in what two phases?
4. The unlit side of the moon ought to be totally black and be unseen in any phase. However, often it can be dimly seen. Why? How does it get any light at all?                    

5. Nebulas were mysterious fuzzy patches of light in space seen in a dark sky. Today we know these are four different things. List them.

6. Put these numbers in order, largest to smallest:   10⁵, 10¹⁴ , 10¹ , 10^-1 , 10^-8 ,10⁰

7. Put these distances in order: ly, megamile, pc, AU. How many km in 1 ly & 1 AU?

8. Put these 14 objects in rough size place (largest to smallest) according to their actual sizes, not as we see them: star (sun), major planet, comet head, meteor, galaxy, universe, a moon, asteroid, comet tail, solar system, local group, minor planet, space out to a nearby star, meteorite, an entire constellation

9. What is the moon illusion and why is it called an illusion?

Answer 1

1. it takes 24 hours and 50 minutes for the earth to complete a lunar day.

=> reason for tides:

the tides formation is a result of interaction of both earth and moon's gravitational fields. where moon pulls ocean water towards it and earth tries to retain it back, causing a deformation on a localised point Called a bulge. this point serves as the origin of tide, from here tides start to travel towards the shore.

=> time taken:

As total lunar day is 12hr 50 mins. During this interval earth experiences two high and two low tides. High tides occur every 12 hours and 25 minutes apart. Whereas, it takes six hours and 20 minutes for the water at the shore to go from high to low.

this is because, during one lunar day two points of tide origin(bulges) tend to occur at a place, forming two high and two low tides. therefore ,

total tides = 2 high +2 low = 4

time taken= 24 hours 50 mins = 24.833 hours

time for each = 24.833 / 4 = 6.20 hours = 6 hours and 12.51minutes (to be exact).

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------

2. A tide basically is a result of sun and moon's upward gravity against earth's downward gravity.

tides caused due to sun - solar tides.

tides caused due to moon - lunar tides.

solar tides are very less effective as compared to lunar tides, but generates a major influence when both lunar tides and solar tides meet together to produce the effect.

There is a time when sun, moon, and Earth are in alignment, then

solar tide + lunar tide = total tide

it takes a week for the sun and moon to be at right angles to each other, at this point solar tide partially cancels out the lunar tide resulting a moderate tide. In a lunar month there are two sets of high and two sets of low tides. that is why in every seven days the tide size changes.

================================================================================================

4. large tides occur when moon is either a full moon or a new moon.(spring tides)

lowest tides occur when a moon is either half moon phasing towards new or a half moon phasing to a full moon.(neap tides)

=================================================================================================

5. Nebulae belong to 4 major groups:

• H II regions
• Planetary nebulae
• Supernova remnant
• Dark nebula

=================================================================================================

6. 1014>105>101>100>10-8>10-1

as 10-8 are 10,9,8

and 10-1 are10,9,8,7,6,5,4,3,2,1. In this a lot many numbers are smaller than the set "10-8"

=================================================================================================

7. ly: 1 leap year = 9,500,000,000,000 kilometers

1 megamile = 1609.34 kilometers

1 perasec =  30,856,776,000,000 kilometers

   1 aeronautical unit = 149,598,000 km

therefore descending order is: 1 pc> 1 lp > 1 au > 1 megamile

=================================================================================================

8.universe>galaxy>constellation>space out to a nearby star>solar system>local group>sun>major planet>minor planet>comet head>comet tail>meteorite.

====================================================================================

9.The Moon illusion is an optical illusion which causes the Moon to appear larger near the horizon than it does higher up in the sky.

this is an illusion because the size of the moon remains the same, although to an observer's eye it might riddle to have changed its size.

-It was fun answering your query, hope you find the detailed explanation to your question.