Chapter 3, Problem 43AP

Review. The instantaneous position of an object is specified by its position vector leading from a fixed origin to the location of the object, modeled as a particle. Suppose for a certain object the position vector is a function of time given by $\stackrel{\to }{r}=4\hat{i}+3\hat{j}-2t\hat{k}$, where $\stackrel{\to }{r}$ is in meters and t is in seconds. (a) Evaluate $d\stackrel{\to }{r}/dt$. (b) What physical quantity does $d\stackrel{\to }{r}/dt$ represent about the object?