In this assignment you will be writing your own function.  This
function will use arguments that are passed using call by value. Call
by value simply means that the value of the argument is passed to the
function parameters.


The distance traveled by an object is often computed using the
following formula in physics:

s = v * t + 0.5 * a * t * t

s is the distance traveled 
v is the initial velocity of the object
a is the acceleration of the object
t is the amount of time that has elapsed

For now you can assume that the units are as follows:
s is in meters
v is in meters per second
a is in meters per second squared
t is in seconds



Write a function that is called distance that has three arguments.
The three arguments will be velocity, acceleration and time. These
arguments should be able to take real values. This function should
compute the distance traveled given the arguments according to the
formula listed above. You should start by making the prototype and
then move on to create the function definition.  A sample main is
given below:



int main() {

    float velocity, acceleration, t, distance;

    cout << "Please input velocity (m/s), acceleration(m/s^2) and time (s):";
    cin >> velocity >> acceleration >> t;

    distance = compute_distance(velocity,acceleration,t);

    cout << "The distance traveled is " << d << " meters." << endl;

    return 0;
}