The law of inertia pertains to both objects at rest and objects travelling in uniform motion (constant rate of motion so acceleration = 0).
ie of an object at rest: A person pushes a building with as much force as possible. The building is at rest and doesn’t move due to its inertia.
ie of an object travelling in uniform motion: An apple is thrown out of a car window. The apple bounces and moves on the ground after it is thrown out the window because of its inertia.
Hope this helps! :)
to plow fields beacuse it's much easier to plow on tractor than on foot
When it comes to optics, the most basic equation to use is the Snell's Law:
n₁ sin θ₁ = n₂ sin θ₂
where θ₁ is the angle of incidence, θ₂ is the angle of refraction, and n are the index of refractions depending on the type of medium.
This equation is used when light strikes from one medium to another and you want to determine the angle of refraction. For example, as light travels from air to water, the light bends as it strike the water. The observable change you can see is that things tend to look bigger when viewed from afar.
In this case, the first medium is air which has an index of refraction of 1. So, n₁ = 1. Then, n₂ is for the glass which is equal to 25°. Substituting the values,
(1) sin 25° = (1.5) sin θ₂
θ₂ = 16.36°
Okay.
So the reason why a certain material would break upon impact is (to really, really dumb it down to save space) because the material is rigid, and not flexible.
So things like glass and hard plastic are not good choices if you want a shatter-resistant container.
Things like Metals are malleable, that means that it can be hammered into thin sheets. Metals are softer and more flexible than materials like glass or hard plastic, so the worst thing that could happen to a metal container when dropped is getting dented, but it won't shatter.
As for where the metals are on a periodic table, take this paragraph from "Chemistry for Dummies":
"<span>In the periodic table, you can see a stair-stepped line starting at Boron (B), atomic number 5, and going all the way down to Polonium (Po), atomic number 84. Except for Germanium (Ge) and Antimony (Sb), all the elements to the left of that line can be classified as </span>metals<span>."</span>
High-frequency sound waves have a shorter wavelength and higher pitch. Frequency, loosely defined, is a measure of how long it takes for a single wavelength to pass a point, so the higher the frequency, the faster the wave is moving, and thus the shorter the wavelength. Pitch (a term used in music) is just another word for frequency, so a wave with high frequency automatically has high pitch.