Describe physical origin of tides
-Moon's tides are about as twice as big as those produced by the sun
-Gravitational attraction of tide-producing body is stronger at point A because it is closer to the sun (noontime or subsolar point) and centrifugal acceleration is weaker
-at point B (m
Why are there two high tides and two low tides per day?
The rotation of the Earth will carry an observer through both high tide bulges (points A and B, noon and midnight) and both low tides (points E and D, 6am and 6pm) once per day
What are spring tides and neap tides? Near which phase of the moon does each type of tide occur?
-Moon dominates and our tides follow the moon, but both sun and moon are important
-Sun produces a prolate shaped tidal bulge whose axis points at the sun, the moon does the same whose axis points towards the moon
-*Our tides are the sum of the two contri
The sun heats the tropical regions of the earth much more than it heats the polar regions. Describe the atmospheric circulation pattern that would be produced by this effect if the earth were rotating very slowly
Two large circulation cells: one spanning the N hemis. and the other the S hemis
-Warm air rises in the tropics, travels poleward at high altitude in each hemis., and cools and sinks near the poles where the heat it carried poleward warms the high latitud
The earth rotates rapidly. Describe the actual circulation pattern on earth.
-Rapid rotation of earth causes the two large cells to split into three cells each
-The highest and lowest latitude cells in each hemisphere circulates the same way as the single large cell did, the air flows equator-to-pole at high altitude and pole-to-e
Describe how the atmospheric circulation and planetary rotation combine to produce the pattern of prevailing winds at low altitude on the earth
Coriolis effect = causes pole-to-equator flow to be deflected into a wind out of the east and equator-to-pole flow to be deflected into a wind out of the west
Equatoiral regions of the earth are moving much faster than the polar regions because of the ear
Describe what happens if a small force acts on an object in a circular orbit in the case where the small force acts in the direction of the orbital velocity.
-Causes the object to move away from the central body in a very tight spiral
-Small force slowly boosts the orbiting object into higher and higher orbits
-Radius of circular orbit slowly gets bigger
-Outer Shepherd
-Leading wake in ring
Describe what happens if the small force and the orbital velocity are in opposite directions
-Causes the orbiting object to spiral towards to the central body in a very tight spiral
-Radius of circular orbit slowly decreases
-Inner Shepherd
-Trailing wake in ring
What prevents the particles in Saturn's rings from coalescing gravitationally and forming a moon?
-The rings are within Saturn's Roche limit = bodies held together by self gravity will be torn apart by tides and cannot exist
-Only bodies small enough to be held together by chemical bonds can orbit within the roche limit --> whereas larger objects are
Left to themselves, the particles in Saturn's rings would spread out and destroy the fine detail in the rings. Why?
-Particles in inner part of ring more faster than those in the outer part
-Collisions between ring particles will equalize speed --> tend to cause fast moving inner ring particles to slow down and fall into higher orbits, while outer ring particles gain s
Describe how the gravitational interaction of the ring particles with the inner and outer shepherd satellites herds the particles into narrow rings and keeps them there
Inner shepherd satellite:
-orbits interior to inner edge of the ring
-The grav. attract. between the satellite and the ring particles produces a density enhancement in the ring
-inner shep. orbits faster than the ring particle --> results in a trailing wa