Is light a wave or a particle?
Both! In the 1800s, Young's double slit experiment displayed the wave-like properties of light. He noticed the light was interfering with itself, similarly to how ripples in a pond can interact with itself. Few years later, Einstein came along and explained the Noble prize winning photoelectric effect. He noticed that when light interacted with a polished metal surface, it would kick out electrons with its momentum, similar to billiard balls. So the answer is both!
Explain Newton's first law of motion.
The first law is what I like to call "the law of teenagers." A teenager at rest wishes to remain at rest until acted upon my an external force (e.g. mom yelling at you) and a teenager in motion will stay in motion unless acted upon by an external force (e.g. mom yelling at you). Now replace the word "teenager" with the word "object" and you have Newton's first law, also known as the law of inertia.
How do you find the components of the resultant for a set of vectors in a 2D plane?
First and foremost, draw a picture of each vector and establish your x and y axes. Next make a two column table, on one side have the x-components and on the other have the y-components for each of your vectors. Take each of your vectors you drew and split them into x and y components, making sure to keep track of your signs while referring to the drawing. Add the two columns. This will give you the x and y components respectively of your resultant!