sponge: tell three reasons reflectors are better than refractors
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Sponge: Tell three reasons reflectors are better than refractors. The Earth has a circumference of 40,000 km and a radius of 6500 km (6378 km). The volume of the solid and liquid parts is 10 27 cm 3 . (no gases or magnetosphere). - PowerPoint PPT PresentationTRANSCRIPT
Its mass is 6.0 x 1027 g.
(6000 billion billion tons)
(Atmosphere and magnetosphere make up less than 0.1% of mass)
For comparison, water has a density of 1 g/cm3, crust rock is 2 to 4 g/cm3. Since the average is 6 g/cm3, the Earth must be much denser below the crust.
This is 40 km compared to a total diameter of 13,000 km; the Earth is smoother and more spherical than a billiard ball.
The Earth has six main regions:
1) Magnetosphere - zone of charged particles trapped by the Earth’s magnetic field.
4) Hydrosphere - oceans
5) Mantle - huge layer of rocky material below the crust and above the core.
There are two high and two low tides each day. The typical change in level from low to high is 1 meter. (In some places it can be as high as 20 m.)
The gravitational influence of the Moon causes a tidal bulge on the side toward the Moon and the side away from the Moon.
Spring tides occur twice per month when the Moon, Earth, and Sun are lined up.
Neap tides occur twice per month when the Moon has moved to a position at a right angle to the Earth-Sun line.
Tidal forces - refers to any variation of gravity across a large body like the Earth or Moon.
This variation of the Moon’s gravitational pull which causes the ocean tides is just one example.