A point moves around a circle, so that the position vector at time $t$ is given by vec$(r)(t)=$hat$(i)cos(4\mathrm{.}86t^2)+$hat$(j)sin(4\mathrm{.}86t^2).$

Part a

The velocity vector is equal the first derivative of the position vector: vec$(v)=$dvec$\frac{r}{d}t.$ What is the speed $|vec(v)|$ at the time $t=2\mathrm{.}83?$

Please enter a numerical answer below. Accepted formats are numbers or $"$e$"$ based scientific notation e$.$g$.0\mathrm{.}23,-2,1$e$6,5\mathrm{.}23$e$-8$

Enter answer here

$31\mathrm{.}82$

$31\mathrm{.}82$

Saved

Part b

The acceleration vector is equal vec$(a)=$dvec$\frac{v}{d}t=d^2$vec$\frac{r}{d}{t}^2.$ What is the magnitude $|vec(a)|$ of the acceleration when $t=2\mathrm{.}83?$

Please enter a numerical answer below. Accepted formats are numbers or $"$e$"$ based scientific notation e$.$g$.0\mathrm{.}23,-2,1$e$6,5\mathrm{.}23$e$-8$

Enter answer here