Engler and Prantl system of classification in plant taxonomy
Tides
1. Tides• The regular rise and fall of water level along a shore is called a “Tide”
• The pull of gravity between Earth and the moon causes tides
.
• The greater the object mass the greater its gravitational pull
• Gravity exists between the Sun and the planets and also
between a planet and its moons .
2.
3. • The pull of gravity changes with distance .
• In case of Earth and moon ,the pull is stronger on the side of
the earth that is facing the moon .
• This causes the Earth’s water to bulge on the moon facing
side of Earth .
• The water level rises where the bulge is and falls where it is
not .
• This causes the regular rise and fall of the tides.
4. • Sometimes ,the way the Sun,Moon and Earth line up causes tides to
be especially strong or weak .
• These tides happens twice a month .
• They depend on the gravitational pull of the moon and the Sun .
5. • When the Sun ,Earth and the moon are in a line ,a spring tide occurs.
• During spring tides ,high tides are higher than usual and low tides are
lower than usual .
6. • If the gravitational pull of the Sun and the Moon are at right
angles ,a neap tide occur.
• During neap tides ,high tides are lower than usual and low
tides are higher than usual .
