Universe: From Big Bang to Planets and Life
The Universe
- It’s a huge vacuum in which billions of galaxies float. For each galaxy, there are thousands of stars, planets, and nebulae.
- Some of them can be seen with the naked eye, and others can be seen with telescopes.
- Formation of the observable cosmos: 75% hydrogen, 20% helium, and 5% the rest of the elements.
Dark Matter
- 90% of the total matter in the universe is dark matter, whose composition and position are unknown because it cannot be seen or emit radiation.
- Proof of existence: A few galaxies
Understanding Vibrations and Waves: Solved Physics Examples
Vibrations and Waves
1) A wiggle in time is a:
A) vibration.
B) wave.
C) both
D) neither
Answer: A
2) A common source of wave motion is a:
A) wave pattern.
B) harmonic object.
C) vibrating object.
D) region of variable high and low pressure.
E) none of these
Answer: C
3) Like a transverse wave, a longitudinal wave has:
A) amplitude, frequency, wavelength, and speed.
B) amplitude, frequency, and wavelength.
C) amplitude, wavelength, and speed.
D) wavelength, speed, and frequency.
E) amplitude, frequency, and speed.
Read MoreUniverse Origins: Glossary of Space and Physics Terms
Universe Origins: Glossary of Terms
Understanding the technical jargon behind the science of the universe’s origins is simplified with this glossary.
- Anisotropy: The variation of a physical property depending on the direction in which it’s measured. For example, the temperature of the cosmic microwave background radiation.
- Antimatter: Material composed entirely of antiparticles.
- Antiparticle: A counterpart to every particle having the same mass but opposite properties at a quantum level (electrical
Windshield Replacement & Repair
Windshield Replacement
First, dismount the vehicle moldings, trims, etc.
Remove windshield wipers and rearview mirror.
Before cutting the adhesive, protect the area around the windshield with masking tape to avoid scratching the paint. Also, protect the interior to avoid damaging the dashboard.
Tools for Cutting Adhesive
- Piano wire or rope
- Oscillating blades
- Heat cutter
- Utility knife for manual cutting
Once cut, remove the windshield using suction cups.
Surface Preparation
Start by removing the remains of
Read MoreEvolution of Astronomical Theories: From Antiquity to Einstein
Evolution of Astronomical Theories
This document outlines the evolution of astronomical theories from ancient philosophers to modern scientists.
Anaxagoras
Anaxagoras proposed that the sun is a fiery metallic sphere. He also explained eclipses and the phases of the moon.
Thales of Miletus
Thales of Miletus is credited with predicting a solar eclipse.
Aristotle
Aristotle believed that the Earth was at the center of a sphere, with the stars fixed in place. He stated that the Earth is fixed and immobile.
Read MoreMotion, Forces, Energy, Waves, and Optics Concepts
Motion: Change in Position
Motion is the change in position of an object relative to a reference point.
Frame of Reference
A frame of reference is a system for specifying the precise location of objects in space and time.
Displacement
Displacement is the change in position of an object. It always includes direction.
Speed
Speed is the distance traveled divided by the time interval during which the motion occurred.
Velocity
Velocity is the speed of an object in a particular direction.
Acceleration
Acceleration
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