Maria Cunitz, famous astronomer of the 17th century, wrote a book on astronomy named “Urania propitia” and, on it, she spread Kepler's theories, revised and simplified his astronomical tables.

Kepler's laws were stated by Johannes Kepler to mathematically describe the motion of the planets in their orbits around the Sun. The Second Law says: "The radius vector  that joins the planet and the Sun sweeps equal areas in equal times", that is, when the planet is further away from the Sun its speed is less than when it is closer to the Sun.

We propose a problem about speeds and planets. Read it and then answer the questions:

• A space rocket is heading towards Jupiter at a constant speed that is 15 times greater than the speed of sound. If the speed of sound is 344.2 m/s and the distance from Earth to Jupiter is 778.3 million km, calculate how long it will take the rocket to reach the planet Jupiter. Express the result in the most appropriate unit of time (the real numbers that appear will be expressed with two decimals).