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.
Gunpowder was, according to prevailing academic consensus, invented in the 9th century in China, and the earliest record of a written formula for gunpowder appears in the 11th century Song dynasty text, Wujing Zongyao.hinese military forces used gunpowder-based weapons (i.e. rockets, guns, cannons) and explosives (i.e. grenades and different types of bombs) against the Mongols when the Mongols attempted to invade and breach city fortifications on China's northern borders.