Unit 1 Flashcards
If the net force acting on the object increases while the mass of the object remains constant, what happens to acceleration?
It increases
If Earth moved to half its current distance from the sun, how would the force of the sun’s gravity on earth change
It’d become 4 times stronger
What did Newton’s Law of universal gravitation tell us about how gravity works?
The force of gravity from the sun will be stronger on an object with more mass
Earth radius is about 6400 km. If in orbit in the space station 150 km up, the force of gravity felt from earth would be
Weaker than when standing on earth
Mars has 1/0 the mass of the Earth and 1/2 the radius of Earth. What’s Mars’s surface gravity relative to that of earth
4/10th
What would happen to earth if the Sun’s gravity turned off instantaneously?
It would continue to move in the same direction it was going in when the gravity turned off
What causes seasons?
The tilt of a body with respect to the plane in which they orbit the sun
Earth’s tilt
23.3 degrees, meaning the Northern and Southern Hemispheres are alternating lay tipped towards or away from the sun
Influence of axial tilt on seasons
Planets with more dramatic tilt have more extreme differences in seasonal temperature differences. Planets with no tilt have no seasons
Why doesn’t distance from the sun matter in seasons?
Bc planets have nearly circular orbits with very little variation
Newton’s Laws
Objects at motion or at rest stay that way unless acted upon by a force
The magnitude of force necessary to produce a certain acceleration on a body will be directly proportional to its mass. More mass = more force
For every action there is an equal and opposite reaction
Force formula
Force = mass * acceleration
When is the moon transiting
When it’s at the highest point in its orbit
When does the waxing crescent rise
9 AM
When does the waning gibbous set
9 am
Lunar Eclipse
Moon is fully visible, but earth’s shadow moves across the moon, covering it partially or completely.
Solar Eclipse
When the moon blocks the sun’s light, or a location on earth is passing under the moon’s shadow
Why don’t solar eclipses happen once a month
The moon’s orbit around earth is tilted 5 degrees relative to earth’s orbit of the sun. The geometry only lines up about twice a year
Penumbra
Moon’s outer shadow, where partial eclipses are seen
Umbra
Moon’s inner shadow, where total eclipses are seen
Inclination
The tilt of a moon’s orbit compared to that of the planet around the sun. Earth’s moon’s is about 5 degrees, explaining the rarity of eclipses
seven principles of design
Balance
Rhythm
Pattern
Emphasis
Contrast
Unity
Movement
Scattering
Reflection or re-direction of light by small particles
Ecliptic Plane
Plane in which the earth orbits the sun. Other planets orbit close to the ecliptic plane
Precessions
The earth wobbling as it rotates
Constellation
Region in the sky
Asterism
A shape traced out in the sky by imagining connecting lines between stars
Zodiac
Subset of constellations crossed by the ecliptic line of the sun
Magnification
Takes view of a small area of sky and blows it up
What happens when you magnify an object with a telescope
Your field of view gets smaller, but its clarity doesn’t change
If you double the width of a telescope’s circular mirrors
Its light gathering power gets multiplied by a factor of four
Refracting telescope
Uses lenses to focus light
Reflecting telescope
Uses mirrors to focus light
Chromatic aberration
Scattering of light’s components
Strength of Gravity Formula
G= M/R^2
Where M is planet mass and R is its radius
More mass means
More gravity
Order of Moon Phases
New – Waxing Crescent – First Quarter – Waxing Gibbous – Full –
– Waning Gibbous – Third Quarter – Waning Crescent
Movement of moon phase
Rises ~6 hours before its overhead and sets 6 hours later
How do you tell what season a constellation is
They are the ones opposite the Sun in a given season
Forms of light (high to low energy)
Gamma Ray, x-ray, UV, visible, infrared, microwave, radio
Relationship between light and color
Energy corresponds to frequency and wavelength
Ex: high energy =high frequency = short wavelength= blue
Low=low=long=red
Blackout spectrum
Higher temperature = more light in total, with a peak at a shorter wavelength
Continuum spectrum
Light at all wavelengths
absorption spectrum
Shows absorption lines (produced when electrons absorb photons) superimposed on a continuum spectrum
Emission spectrum
Shows emission lines (produced when electrons jump from higher to lower energy levels, emitting photons of those specific energies
Important telescope qualities
light gathering power, angular resolution, and power. Magnification doesn’t really matter
How do telescopes gather light
In proportion to the area of their mirrors (proportional to diameter^2)
Angular resolution
Ability to distinguish or separate two nearby light sources (with good angular resolution). Limited by Earth’s atmosphere
