Question 1138515


As the question tells, the instantaneous velocity is the first derivative of the position.

 position equation given: {{{s(t) = 3 - 4t}}}

derivative, {{{v(t)}}} = {{{s}}}'{{{(t)}}}

{{{s}}}'{{{(t)}}} = [{{{ 3 - 4t}}}]' = {{{(3)}}}' - {{{(4t)}}}' = {{{0}}} - {{{4}}}({{{t}}}') = {{{- 4}}}

Then, the velocity is constant (does {{{not}}} depends on {{{t}}}), and its value is {{{- 4}}}.