Physics Flashcards
What is the life cycle of a star in order?
Nebula, protostar, main sequence, red giant/ supergiant, supernova and white dwalfs
What is the milky way
The Milky Way is the galaxy that contains our solar system. It’s a barred spiral galaxy, with a central bulge, a disk, and spiral arms filled with stars, dust, and gas. Our Sun is located in one of the spiral arms.
how far is a light year?
Light Year is the distance light travels in one year (about 9.46 trillion kilometers).
Scale of the universe
Light Year is the distance light travels in one year (about 9.46 trillion kilometers).
What are telescopes useful for?
Telescopes are used to observe distant objects in the universe. They can be optical (visible light), radio, or space-based (Hubble, James Webb).
What is the electromagnetic spectrum?
The Electromagnetic Spectrum includes different types of waves based on wavelength: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Each type of wave gives us different information about the universe.
What is the big bang theory?
The Big Bang Theory proposes that the universe began as a singularity and expanded over 13.8 billion years.
What is the evidence behind the big bang theory?
Cosmic Microwave Background Radiation: Residual heat from the Big Bang.
Redshift: Galaxies are moving away, indicating the universe is still expanding.
Abundance of Elements: Predicted amounts of hydrogen and helium match observations.
What is the doppler effect?
The Doppler Effect refers to the change in frequency or wavelength of waves as the source moves relative to an observer..
How does the doppler effect work?
Redshift: If a galaxy moves away, its light is stretched, shifting to the red end of the spectrum.
Blueshift: If a galaxy moves toward us, its light is compressed, shifting to the blue end.
What is the spectra of stars?
Spectra refer to the patterns of light that stars emit. By analyzing these spectra, astronomers can determine:
Temperature: Hotter stars emit light at shorter wavelengths.
Composition: Different elements absorb light at specific wavelengths, creating absorption lines.
Movement: The Doppler shift of spectral lines reveals whether a star is moving towards or away from us.
How to calcucate speed?
Speed = Distance ÷ Time (scalar quantity).
How to calculate acceleration (velocity)
Acceleration = (Final Velocity - Initial Velocity) ÷ Time
What is Newtons first law (force)
An object at rest stays at rest, and an object in motion stays in motion, unless acted on by an external force. This is also known as the law of inertia.
Objects resist changes in their state of motion.
What is Newtons second Law (forces)
Force = Mass × Acceleration. This law explains how the force applied to an object affects its motion.
The greater the force or the smaller the mass, the greater the acceleration.
What is Newtons Third Law (Forces)
For every action, there is an equal and opposite reaction.
When one object exerts a force on another, the second object exerts an equal force in the opposite direction.
What is a star?
Hot, gaseous spheres that are made mostly from hydrogen and helium
What is a constellation?
Fixed groups of stars that are named according to the patterns that they seem to form in the sky.
What is a nebula?
Clouds of dust and gas that are the ‘nurseries’ of stars.
What is a galaxy?
System of millions or billions of stars, together with gas and dust, held together by gravitational attraction
What is a exoplanet?
Planets that are observed in solar systems other than our own.
What is a protostar?
Very young star that is still gathering mass from its parents nebulae.
Explain why we can ‘look back in time’ when we look at distant objects in space.
We “look back in time” when viewing distant objects in space because their light takes millions or even billions of years to reach us, showing them as they were in the past.
What is the difference between a reflector or refractor telescope.
A reflector telescope uses mirrors to gather and focus light, while a refractor telescope uses lenses for the same purpose.
