Physics

Problem

A particle has position vector

\mathbf{r}(t)=2t^{3}\,\hat{\mathbf i}+4\sin t\,\hat{\mathbf j}+5e^{0.5t}\,\hat{\mathbf k}

(metres). Find the magnitude of its instantaneous velocity at

t=0

. a)

6.50\;\text{m/s}

4.00\;\text{m/s}

4.72\;\text{m/s}

6.40\;\text{m/s}