A Particle Moves Along a Straight Line with Equation of Motion

Multiple Choice

A particle moves along a straight line with equation of motion $s = t ^ { 3 } - t ^ { 2 }$ . Find the value of t at which the acceleration is equal to zero.

A) $- \frac { 2 } { 3 }$
B) $- \frac { 1 } { 3 }$
C) $\frac { 2 } { 3 }$
D) $\frac { 1 } { 3 }$
E) $- \frac { 1 } { 2 }$
F) $\frac { 1 } { 2 }$
G) $- \frac { 3 } { 2 }$
H)
$\frac { 3 } { 2 }$