sspace - orbital motion Flashcards
what is a circular orbit?
where a planet (for example earth around the sun) follows a path of a circle
what’s an elliptical orbit?
an elliptical path
The earth’s orbit is….
virtually circular
how do planets orbit the sun?
by the force of gravity acting between the Sun and the planets. this holds the planets in their orbits
what is the moon?
a natural satellite - again gravity between moon and earth holds it in its orbit
what are artificial satellites?
man-made
how often do geostationary satellites orbit Earth? what does this mean?
every 24 hours which means they always point to the same point of earth but other artificial satellites orbit more frequently
how does the force of gravity lead to a change in velocity when an object is in circular orbit?
(DOESNT CHANGE SPEED) velocity = speed of object in given direction
- direction constantly changing which means so is velocity. speed is constant. force of gravity changing velocity but not the speed
what must change if speed of satellite changes in a stable orbit?
the radius of orbit must also change. if speed of satellite increases, then the radius of its orbit decreases. because at a higher speed, the satellite needs a greater force of gravity to prevent it from flying off into space. by moving closer to the Earth, the gravitational force on the satellite is greater and the satellite remains in a stable orbit. (true for planets and moons as well)
