A study on a dangerous rock in the Yangtze River in China found that it is made of two types of limestone. The rock has fissures that can cause it to break and slide. By using a special model, the researchers calculated that the rock can break at a speed of 531.4 m/s^2 and slide at 2.608 m/s. The top and bottom of the rock move at different speeds, causing it to slide backwards. This study helps us understand how giant rocks in the Yangtze River can break and slide, which is important for navigation safety.