A point travels along the $x$-axis so that at time $t$ its position is given by $s(t) = t^3 - 5t^2 + 4t$, where $0 ≤ t ≤ 5$.

1. ​What does $s(t)$ represent?

   Answer (a):

   The point's position along the $x$-axis.

2. Where is the particle located when $t = 5$?

   Steps (b):

   Calculate $s(5)$.

3. What is the velocity of the particle when its acceleration is zero?

   Hint (c):

   Velocity is the derivative of position, and acceleration is the derivative of velocity.