To calculate distance given acceleration, initial speed, and final speed, the correct equation is v^2 = u^2 + 2as, where v is the final speed, u is the initial speed, a is acceleration, and s is displacement. It is important to rearrange the equation to solve for s. In scenarios involving deceleration, the acceleration value should be negative, such as -2.68 m/s². This approach ensures accurate distance calculation in motion problems. Understanding these principles is crucial for solving related physics questions effectively.