Newtons Second law of Motion is what explains how Acceleration works. It says that acceleration is directly connected to how much Netforce is put onto it. This has a for a equation that goes with it to explain it. F = M X A. Force is what the Mass of the object X the Acceleration of the object. This also makes Acceleration = Force/Mass. The more force put onto an object, the faster it will go, but the bigger the Mass, the slower it will go. This is important because it makes sure you know how moving things work even though you probably have figured it out by living.
Newtons 3th law of Motion is what tells us how every action has an oppsite response to it. This explains that when one object puts force onto the another, the other object puts force back onto it in the oppsite way that the first object did to it. Inertia is the thing that decides if a object moves or not. Mass and Inertia are related as if the object has more Mass, it will take more inertia to make it more. The smaller Mass, the less inertia it will take. It's like how when you're in a car and it breaks, you're pushed forward, that's because of inertia.
The Elctromagneitc Spectrum is the spectrum that is used by scientists use to tell what Waves are which. Its a spectrum that shows which waves are which, which shows the waves, the wavelengths, and how much Energy they produce. Amplitude is the displacement from which a wave starts at its resting point. Frequencey is the rate of the waves meaning the less frequencey, the less waves, which also means their longer, and if we use that thought process, that means that the more frequencey, the shorter the waves but the more of them. A Wavelength is the length put between the wave peaks, which can be short or long determined on how high or low the frequencey is. The longest waves are (Longest to Shortest) - Radio Waves, Micowaves, Infrared. The shortest waves are (Longest to Shortest) - Ultraviolet, X-Rays, Gamma Rays. The wavelengths are related to energy as the shorter the wave, the more energy it puts out. Think of it that each peak that is shown on a wave, thats when it puts out energy, which also means that the longer ones, put out less energy then the shorter ones.
The life of a star starts at Hydrogen turning into Helium, making a load of Energy called a Nuclear Furance. That is just the start, they start as a Cloud of Gas - Nebulae. The gas will Dense up into a little mass in the cloud, as it grows it makes a Proto Star. It will continue to condense, causing heat to build up, evenutally making a Main Sequence Star. This is where it takes 2 different routes which are determined by the size of the star. They use the gases that they were born with as fuel, so when they run out of that fuel, they expand to either a Red Giant, or a Red Super Giant. Regular or small stars turn to Red Giants, and Massive stars turn to Red Super Giant. The Red Giants will turn to Planetary Nebula which when die, will turn to White Dwarfs that are hot so when cooled, turn to Black Dwarfs. Meanwhile with Red Super Giants, they will turn to a Supernova, but instead of 1 determined path, it has 2. Supernovas can turn to either BlackHoles or a Neutron Star.
A HR diagram is a diagram made to show stars on a graph with how Hot they are and how Bright they are. The Y-axis is used for the Brightness and the X-axis is used for the Temperature. There are 4 Types of Stars on the diagram, and those are - Main Sequences, Giants, Super Giants, and White Dwarfs. Smaller stars tend to be less bright and less hot. The Hottest stars are usual to the left side while cooler ones are on the right side. While Brighter stars are usual are on the top of the graph while dimmer one are at the bottom of the graph. Our Sun is actually a Main Sequence Star, so it will go boom one day.
Galaxies are areas in space that are like a big ball bound with gravitationally of Gas, Dust, and Dark matter. Not to mention stars, lots of stars. They can have millions apon millions of stars. There are actually 3 types of galaxies that can happen - Spiral, Elliptical, and Irregulars. Spiral - It looks like it has arms, in a circally sharp. The arms all seem to wind in like if you cook a egg and use something to twist the middle one way. They have Older Stars in the edges while Younger Stars are usually more in the middle. Elliptical - They look like a Dot. They usually have old, red stars, just a little of gas and some dust. When you see photos it's like when you look at a bright light for 2 long, and you have a dot in your vision. Irregulars - These really have no shape to them most times, more just like absart shapes that are made up of lots of gas and dust, with parts having more stars in some spots.