A Particle Moves in a Straight Line with Its Displacement $s ( t ) = t ^ { 2 } - 3 t + 5$

Essay

A particle moves in a straight line with its displacement of motion described by equation $s ( t ) = t ^ { 2 } - 3 t + 5$ , where $s$ is measured in feet and $t$ is measured in seconds. Find the velocity of $$s$$ at $t = a$ , $t = 2$ , $t = 4$ , and $t = 6$ .