$${dV \over dt} = {\operatorname{change in volume} \over \operatorname{respect to time}}$$
-` |->--diff-->--| |-->--diff-->--|
-displacement velocity acceleration
- |--<-antidiff-<---| |--<-antidiff-<-|`
-
-**displacement $x$** - change in position
-**velocity $v$** - change in displacement
-**acceleration $a$** - change in velocity
+**position $x$** - distance from origin or fixed point
+**displacement $s$** - change in position from starting point (vector)
+**velocity $v$** - change in position with respect to time
+**acceleration $a$** - change in velocity
+**speed** - magnitude of velocity
$$v_{\operatorname{avg}}={\Delta x \over \Delta t}={{x_2 - x_1} \over {t_2 - t_1}}$$
$$\operatorname{speed}_{\operatorname{avg}}={\Delta v \over \Delta t}$$