Il A heavy ball with a weicht of 100 N (m 10.2 kg) is hung. from the ceiling of a lecture hall on a 4.5-m-long rope. The ball. is pulled to one side and released to swing as a pendulum, reach-. ing a speed of 5.5 m/s as it passes throuoh the lowest point.
Inventions. The huochong gun was invented in China during the Ming dynasty. It was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.t was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.
Cast Iron: An Invention of Ancient China. By Karin Alsop, Claire Deng, & Karen Kwan. A drawing of an early blast furnace. inventor unknown. earliest cast iron artifact found in Jiangsu. Mass-production began in the Han dynasty. At the time of its invention, cast iron had many uses. Since the discovery of steel, iron (both cast and wrought) has become less common, as steel is generally stronger. Cast iron is still used in buildings, although they are usually older or decorative ones.