8b-Motion in the universe Flashcards
Q: What is the structure of the universe?A:
The universe is a vast collection of billions of galaxies.
A galaxy is a large collection of billions of stars.
Our solar system is located in the Milky Way galaxy.
Q: Why does gravitational field strength vary across different planets?A:
Gravitational field strength (g) depends on mass and radius of a celestial body.
Larger, more massive planets have stronger gravity.
The Moon has weaker gravity than Earth due to its smaller mass.
celestrial body’s GFS: earth
Earth
9.8
celestrial body’s GFS: moon
Moon
1.6
celestrial body’s GFS: mars
Mars
3.7
celestrial body’s GFS: jupiter
Jupiter
24.8
Q: How does gravity influence motion in space?A:
Moon
Moons orbit planets due to gravitational attraction.
How does gravity influence motion in space?
Planet
Planets orbit the Sun because of the Sun’s gravity.
How does gravity influence motion in space?
Artificial satelite
Artificial satellites orbit the Earth for communication and observation.
How does gravity influence motion in space? Comet
Comets orbit the Sun in highly elliptical paths.
how does planet orbit
Planets
Nearly circular
Orbit the Sun in elliptical orbits
how does Moon orbit
Moons
Circular
Orbit planets in regular paths
how does Comets orbit
Comets
Highly elliptical
Speed changes significantly as they approach the Sun
Why do comets change speed in their orbits?A:
As a comet approaches the Sun, its speed increases due to stronger gravitational pull.
As it moves away from the Sun, it slows down.
Practical: Investigating Orbital Motion
Simulating Planetary Orbits
Method: Use a rotating ball on a string to represent orbital motion.
Observation: Faster rotation (higher speed) keeps the ball in orbit, similar to planets.
Conclusion: Confirms how gravitational pull and velocity interact in orbital motion.
