Consider the axis and unit vector shown in Figure 2.18. Let the vector \(\vec{r}\) have its tail at the origin and its tip at my feet.

(a) What is the \(x\) component of that vector?

(b) Write the vector \(\vec{r}\) in terms of its \(x\) component and the unit vector.

(c) What does the vector \(\vec{r}\) represent?

(d) Does \(r_{x}=+2.5 \mathrm{~m}\) unambiguously determine a vector in Figure 2.18? If so, draw the vector, and state what it might represent.

Figure 2.18 The unit vector i completely specifies a reference axis. The unit vector's direc- tion determines the direction of increasing x along the axis. The tail of the vector locates the origin, and its length defines the unit. x (m) 2 3 4 5