Io's metallic core makes up approximately 20% of its mass. Depending on the amount of sulfur in the core, the core has a radius between 350 and 650 km (220â400 mi) if it is composed almost entirely of iron, or between 550 and 900 km (340â560 mi) for a core consisting of a mix of iron and sulfur.
In 1886, Karl Benz developed a petrol- or gasoline-powered automobile. This is also considered to be the first production vehicle as Benz made several other identical copies. At the turn of the 20th century electrically powered automobiles appeared but only occupied a niche market until the turn of the 21st century.
The early history of the automobile can be divided into a number of eras, based on the prevalent means of propulsion. Later periods were defined by trends in exterior styling, size, and utility preferences. In 1768, the first steam powered automobile capable of human transportation was built by Nicolas-Joseph Cugnot.he first carriage-sized automobile suitable for use on existing wagon roads in the United States was a steam powered vehicle invented in 1871, by Dr. J.W. Carhart, a minister of the Methodist Episcopal Church, in Racine, Wisconsin.