Which vector quantity was historically used to help sailors determine direction at sea?

Given the vector function $r\left(t\right)=\left[t^2,\frac{2}{3}{t}^3,t\right]$, find the unit tangent vector $t$, the unit normal vector $n$, and the unit binormal vector $b$ at the point $\left[1,-\frac{2}{3},-1\right]$.

An object is placed in front of a thin converging lens. Which of the following statements correctly describes the nature of the image formed when the object is located at a distance greater than twice the focal length from the lens?$d>2f$

In the context of vectors, which of the following best describes the angle $\theta$ between two vectors $A$ and $B$?

A uniform beam of length $l$ is supported at its ends. Where is the center of mass of the beam located along its length?

Given that an object is placed $16.0\mathrm{cm}$ to the left of a lens and the lens forms an image $36.0\mathrm{cm}$ to the right of the lens, what is the focal length of the lens?

If $\stackrel{1}{v}$ and $\stackrel{2}{v}$ are perpendicular vectors, which of the following is true?

In the context of vector analysis, if a Howe truss is subjected to a downward force of $500 N$ at its center joint, which vector best represents the direction and sense of the applied load?