90
edits
Changes
Jump to navigation
Jump to search
Line 130:
Line 130: − + − + − + + + + + − Kepler's laws were derived for orbits around the sun, but they apply to satellite orbits as well. For details of Kepler's laws click [http://karnatakaeducation.org.in/KOER/en/index.php/Kepler's_Laws here]. <br><br>
Significance of Gravitational Force (view source)
Revision as of 11:44, 4 December 2013
, 11:44, 4 December 2013→Concept #2 - Kepler's Laws
Johannes Kepler, working with data painstakingly collected by Tycho Brahe without the aid of a telescope, developed three laws which described the motion of the planets across the sky.
Johannes Kepler, working with data painstakingly collected by Tycho Brahe without the aid of a telescope, developed three laws which described the motion of the planets across the sky.
<br><br>
<br><br>
#The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.<br><br>
#The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.<br>
#The Law of Areas: Each planet moves so that an imaginary line drawn from the Sun to the planet sweeps out equal areas in equal periods of time.<br><br>
#The Law of Areas: Each planet moves so that an imaginary line drawn from the Sun to the planet sweeps out equal areas in equal periods of time.<br>
#The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.<br><br>
#The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.<br>
Kepler's laws were derived for orbits around the sun, but they apply to satellite orbits as well. For details of Kepler's laws click [http://karnatakaeducation.org.in/KOER/en/index.php/Kepler's_Laws here]. <br>
Accurate measurements on the orbits of the plantes indicated that they did not precisely follow Kepler's laws. Slight deviations from perfectly elliptical orbits were observed. Newton was aware that this was to be expected from the Law of Universal Gravitation. The derivation of perfectly elliptical ignores the forces due to the other planets. These deviations called perturbations are observed and led to the discovery of Neptune and Pluto. Planets around distant stars were also inferred from the regular wobble of each star due to the gravitational attraction of the revolving plant.
===Activity No # ===
===Activity No # ===
{| style="height:10px; float:right; align:center;"
{| style="height:10px; float:right; align:center;"