The displacement vector (SI units) is
![\vec{r} =At\hat{i}+A[t^{3}-6t^{2}]\hat{j}](https://tex.z-dn.net/?f=%5Cvec%7Br%7D%20%3DAt%5Chat%7Bi%7D%2BA%5Bt%5E%7B3%7D-6t%5E%7B2%7D%5D%5Chat%7Bj%7D)
The speed is a scalar quantity. Its magnitude is

Answer: At√(t⁴ - 12t³ + 36t² + 1)
A. Plasma
That is your answer!
Any sample of an <em>ELEMENT</em> is made of only one type of atom.
Here are some elements:
-- Hydrogen, Helium, Neon
-- Carbon (lead in a pencil, also diamonds)
-- Oxygen, Nitrogen, Argon (All mixed together in air, but not hooked up with other atoms)
Other elements you may have heard of:
-- Silver, Gold, Copper, Iron, Lead, Aluminum, Silicon, Chlorine, Calcium, Titanium, Nickel, Tin, Platinum, Mercury, Radium, Uranium