String material = getLineFromInput();
int temperature;
float speed_of_sound;

switch(material) {
    case "air":
        temperature = getLineFromInput();
        speed_of_sound = 331.5 * blah blah blah;
        break;
    case "whatever":
        speed_of_sound = 50;
        break;
}

printOutput(speed_of_sound);