$C4{10}^{-1}$ grams.

$D4{10}^3$ grams.

$E4{10}^{-6}$ grams.

$2.$ The distance $d$ that a certain particle moves may $be$ calculated from the expression $d=at+b{t}^2$ where a and $b$ are constants; and $tis$ the elapsed time. What must the dimensions $of$ the quantities a and $bbe,$ respectively?

$A\frac{[L]}{[T]},\frac{[L]}{[T{]}^2}$

$B[L],[L{]}^2$

$C\frac{[L]}{[T{]}^2},\frac{[(L)]}{[T{]}^3}$

$D\frac{[L]}{[T]},\frac{[L{]}^2}{[T{]}^2}$

$E\frac{1}{[(T)]},\frac{1}{[(T){]}^2}$

$3.$ Which one $of$ the following quantities $is$ a vector quantity?

$A$