From $t=0$ to $t=4\mathrm{.}67$min, a man stands still, and from $t=4\mathrm{.}67$min to $t=9\mathrm{.}34$min, he walks briskly in $$ straight line at a constant speed of $2\mathrm{.}67\frac{m}{s}.$ What are $($a$)$ his average velocity $v_{\text{a}\text{v}\text{g}}$ and $($b$)$ his average acceleration $a_{\text{a}\text{v}\text{g}}$ in the time interval $1\mathrm{.}00$ min to $5\mathrm{.}67$ min $?$ What are $($c$)v_{\text{a}\text{v}\text{g}}$ and $($ d $)a_{\text{a}\text{v}\text{g}}$ in the time interval $2\mathrm{.}00$ min to $6\mathrm{.}67$ min $?$

$($a$)$ Number

Units

$($b$)$ Number $$ Units

$($c$)$ Number $$ Units $$

$($d$)$ Number $$ Units