Coriolis_Effect - Earth,Space and Life - Science

Earth,Space and Life - Coriolis Effect

1. Coriolis Effect

2. 2. Evidence for Rotation
Coriolis Effect –the tendency of objects moving over the
earth (air, water, planes, projectiles) to be deflected
(curve away) from a straight line path. The French
scientist, Gaspard Coriolis, first explained the deflection
of objects moving over the surface due to Earth’s
rotation
The deflection is to the right in the Northern Hemisphere
and to the left in the Southern Hemisphere.
This deflection occurs because Earth’s surface is rotating
with respect to the objects.

3. www.youtube.com/watch?v=_36MiCUS1ro

7. Actual motion

9. North Pole Projectile
A hockey puck is
launched from the
north pole. As it heads
south, the earth turns
to the east, causing the
puck to appear to
deflect to the west as
viewed by an
earthbound observer.
Legend:
Red: Path on rotating
earth
Gray: Path on
stationary earth

10. Coriolis Effect
The tendency for any moving body on or
above the earth's surface, e.g., an ocean
current, wind or an artillery round, to drift
sideways from its course because of the
earth's rotation.

11. The true shape of the Earth called
an Oblate Spheroid.
The diameter from the North Pole to the South
Pole (the shortest diameter) is approximately
12,714 km. The equatorial diameter (the longest
diameter) is approximately 12,756 km. This is
nota big difference, but it does make the Earth
not quite a sphere.

13. •Something hanging from
a fixed point which, when
pulled back and released,
is free to swing down by
force of gravity and then
out and up because of its
inertia.
•Inertia:means that
bodies in motion, will stay
in motion; bodies at rest,
will stay at rest, unless
acted on by an outside
force.
Don’t Copy

14. 1. Evidence of Earth’s Rotation
1851, Foucault’s pendulum will appear to change
in a predictable way.
Why is this evidence? There is no force acting
on the pendulum to make its plane of oscillation
rotate or go around its own axis
It would continue to swing in the original path if
Earth did not rotate.

15. No force that makes pendulum rotate –
must be earth that is rotating!!!

17. Foucault pendulum
As you watch the pendulum for just a
short time, it will appear to be moving
clockwise across the mosaic map on the
floor.
But, since there is no outside force making
the pendulum rotate as it swings, and no
other outside force interrupting the swing,
it must be the floor itself that is rotating,
while the path of the pendulum’s swing
remains constant.

19. What are the APPARENT
MOTIONS of Celestial Objects
An apparent motion can be real or an
illusion
For example, the stars appear to move
across the sky from east to west
However, the apparent motion is caused
by Earth’s rotation

20. Pointer Stars point to Polaris

21. •Looking upward we see the stars
fixed on the celestial sphere
•Earth’s eastward rotation makes
the stars between the equator
and north celestial pole appear to
move westward
•Rise in the east and set in the
west.
•Timed photography showing
stars rising in the east

22. Earth’s counter clockwise rotation
makes the stars appear to rotate
counter clockwise around the north
celestial pole (Polaris).

24. Evidence of Earth’s Revolution
around the Sun
Seasonal Constellations:Because of the
Sun’s annual motion, some constellations
are visible at night only during certain
seasons.
Constellations are visible when the dark
side of Earth (away from sun) faces
toward the constellation.

25. The 13 constellations the sun
appears to travel through during
the year