Solve all four questions and PLEASE show work... I will mark you brainliest and rate you five stars

Given the distance function d(t) = 0.8t^2, we must derive the formula to get the formula for velocity. The first derivative of a distance function gives the velocity because it shows how the variable (distance) changes over a another variable which is usually time. Following the same line of thought, the second derivative gives the acceleration.

dt = 2(0.8)t = 1.6t = 1.6(10) - 1.6(5) = 8 m/s