astroworld Flashcards
newton’s universal law of gravitation
the gravitational force of attraction b/w two point masses is directly proportional to the product of the masses and inversely proportional to the square of the distance between them.
the force acts along the line joining the two point masses.
G=6.67*10^-11 Nm^2Kg^-2
gravitational field strength
force per unit mass experienced by a small mass
center of mass
point at which entire mass is assumed to be concentrated
center of gravity
point at which entire gravitational force is assumed to be concentrated
law of orbits
all planets revolve around the sun in elliptical orbits with the sun at one of the two focal points
infer: distance of planets from sun is never const.
law of areas
the radius vector sweeps out equal areas in equal time intervals
area swept is equal but the distance covered is not.
which means that planets travel faster closer to the sun due to higher gravitational force.
and the speed of the planet is not always const. (higher speed closer to sun which is why able to cover greater distance in same time)
law of periods
the square of the time period of a planet around the sun is directly proportional to the cube of the semi major axis
circular motion
if at all a body travels in a closed structure, changing its direction of motion at every point, while maintaining a constant distance from a reference point
uniform = if body travels in circular path w/ constant speed
centripetal acceleration
the acceleration of a body moving in a circular path
centripetal = central seeking
direction of acceleration is towards the center
a=v^2/r
centripetal force
force that pulls an object towards its center
at every point of the path, the object will experience a force pulling it towards the center
not an extra force, a type of force plays the role of centripetal force. ex. gravitational force in sun, earth or tension in rotating icard
if body is in circular motion, the net force acting on the body is the centripetal force.
F=m*(v^2/r) [F=ma]
objects in the universe
solar system
stars
milky way galaxy
cluster of galaxies
universe
multiverse tys?
solar system
sun
planets
- mercury
- venus
- earth
- mars
- jupiter
- saturn
- uranus
- neptune
satellites
asteroid belt
kuiper belt
oort cloud
coment
bb theory
the enthire universe as we see today is moving away (expanding). therefore a few billion years ago this enthire matter might have been present at a single point which could have exploded with a big bang!
exploded because so much pressure, mass at one point
where was dot? how tf do ik?
1 proof of bb
measured wavelength from galaxies and noticed red shift (increasing wavelength)
which means they’re moving further away from us which means they were all at one point sometime.
2 proof of bb
for every explosion em waves are given out/will remain.if at all bb took placed, em waves should be given out and those waves must spread all around the universe.
well, indeed, cosmic microwave background radiation exists and is present throughout the universe, hence proving the idea of the explosion.
3 proof of bb
if at all bb had taken placed, scientists predicted the composition of H and He.
predictions matched experimentally observed, hence proving the bb theory.
hubble’s law
the recession velocity of a galaxy is directly proportional to the distance b/w the galaxies
v=H_0*d
H_0 = age of universe
