## 2 Experimental Introduction
### Experimental Procedure
#### 2.5.1 Influence of Block Shape on Rolling Speed
In contrast, for test block D, despite having a slenderness ratio within the range of \(1>\lambda>0.33\), the small resistance of the initial rolling section upon release prevents a change in the rolling axis, resulting in minimal lateral offset, similar to test block G. This observation indicates that when rolling on a slope without obstacles, the transformation of the rolling axis of the test block is positively correlated with both the slenderness ratio and the rolling resistance originating from the shape of the test block itself. From Figure 14, it is evident that at a release height of 45 cm, despite block D having slightly greater roundness compared to block K, its rolling speed (2.23 m/s) is slightly lower than that of block K (2.26 m/s). The reason for this phenomenon is that during the rolling process, block K's moment of inertia is greater than that of block D, allowing block K to possess more rotational kinetic energy when rolling down the slope, as depicted in Figures 17 and 18. Consequently, block K overcomes some of the rolling resistance caused by its shape, leading to its rolling speed approaching that of block D, and in some cases, even surpassing it. Although the contact area between test block K and the rolling surface is smaller than that of test block D, the center of gravity of test block K is higher than that of test block D, resulting in the left and right shaking of test block K during the rolling process. However, under the action of rotational inertia, it can still maintain the initial rolling axis. The shaking of test block K during the rolling process consumes some of the rolling kinetic energy, resulting in a decrease in the rolling speed of the test block. Figure 15: Actual rolling of Block G at a height of 45 cm and 60\({}^{\circ}\) slope. Figure 16: Actual rolling of Block E at a height of 45 cm and 60\({}^{\circ}\) slope. Figure 17: Actual rolling of Block D at a height of 45 cm and 60\({}^{\circ}\) slope. 2.5.2. Influence of Slope and Release Height on Rolling Speed of Test Blocks with Different Shapes  
For the spherical test block A, which can ignore the rolling resistance caused by its own shape, under the same release height, its rolling distance and slope offset will decrease with the increase of the slope. Additionally, the rolling resistance required to overcome the slope characteristics will also decrease. It can be observed that for spherical test blocks, under the same conditions as other influencing factors, the rolling speed is positively correlated with the slope angle. In other words, for test blocks with high rolling resistance, a decrease in slope at the same height will increase the rolling distance of the test block on the slope, thereby increasing the energy consumption of the test block. When the slope is gentle and the rolling distance is too long, there may be a situation where the rolling speed of the test block continues to decrease and eventually stops on the slope. As seen in Figures 12-14, for the test block released at rest, with the increase in the release height, the test block has greater gravitational potential energy when released, and the rolling speed of the test block with all shapes increases with the increase in the release height. However, the increasing amplitude of the rolling speed of different test blocks with the increase in the release height is very different. The most noticeable difference is the change in the rolling speed of test block A and test block B with the increase in height in Figure 12. The increase in rolling speed of test block A is much greater than that of test block B. It can be observed that for a test block with high rolling resistance, increasing its release height on the slope has no obvious effect on its rolling speed. However, this phenomenon mainly occurs when the slope is small. As shown in Figure 13, when the slope is 45\({}^{\circ}\), the increase in the rolling speed of all test blocks can be clearly observed with the increase in release height.