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.
This was 150 years earlier than the cannon was developed in the west. The Song people also used gunpowder to make fire lances, or flamethrowers, and anti-personnel mines (for which we might be less grateful!). By the end of the Song Dynasty the Chinese had invented multi-stage rockets.his was a century earlier than the compass was first mentioned in Europe in 1190. The compass was further developed in the 8th Century AD when magnetised needles replaced loadstone, and between 850 and 1050 they became common as navigational devices on ships.