The spoked wheel was invented more recently, and allowed the construction of lighter and swifter vehicles. The earliest plain examples are in the context of the Andronovo culture, dating to ca 2000 BC. Shortly later, horse cultures of the Caucasus region used horse-drawn spoked-wheel war chariots for the greater articulation of three centuries. Celtic chariots fascinating an heavy rim around the wheel in the 1st millennium Wheels BC. The spoked wheel had been in continued bag without greater modification until the 1870s CE, when wire wheels and pneumatic tires were invented.
Now give the jobby 4 wheels. The normal exaction between the 4 wheels and axles is the same (in total) 981 N, assume ü = 0.1, and say the wheel diameter is 1000 mm and axle diameter is 50 mm. So while the reality still moves 10 m the sliding frictional surfaces only move along over each other a distance of 0.5 m. The commission done is 981 x 0.1 x 0.5 = 49 joules.
