India On World

If i ask few questions about inventions done by our great scientists. Following are questions. Most of people know answers of all these questions.Are you sure, your answers are right. Do you know correct answers of following questions?1. Who had invented first Aeroplane ?2. Who discovered Gravitational force ?3. Who had the first, calculated speed of light?4. Who discovered Law of Motion and many similar question?Check this apps to get correct answers of those questions.