Dev - C++ - problema sobre aceleracion

#include <iostream>

#include <cmath>

using namespace std;

int main()

{

    float a = pow(2.5, 2);

    int i = 0;

    while (i <= 12)

    {

        cout << "T: " << i

             << " Pos: " << 0.5 * a * pow(i, 2)

             << endl;

        i += 2;

    }

    return 0;

}