你是一位物理老师，需要给学生讲解这个题目。要分析每一个运动过程。---**Question 42:** **Question Stem:** "智勇大冲关"最后一关有如图所示的滑道，冲关者坐上坐垫（冲关过程中人和坐垫不分离）从 A 点静止开始沿倾斜直轨道 AB 滑下，斜道倾角 $\theta=37^\circ$; CD 是一长 L=3m 的水平传送带，B 与 C 两点平滑衔接，A 点距传送带垂直距离为 h=2.4m，冲关者经 C 点到 D 点后水平抛出，落在水面上一点 E。已知：传送带末端距水面高度 H=0.8m，坐垫与 AB 斜道间动摩擦因数为 $\mu_1=0.5$，坐垫与传送带间动摩擦因数为 $\mu_2=0.2$，冲关者的质量为 m=50kg，坐垫质量忽略不计，sin37°=0.6，cos37°=0.8，g=10m/s²；求： **(1) 冲关者到达 B 点时的速度大小 $v_B$；** **(2) 如果传送带不动，求冲关者落到水面 E 点与 D 点的水平距离 x；** **(3) 如果传送带速率为 1m/s 沿逆时针方向转动，求冲关者与传送带之间因摩擦产生的热量 Q。** **Given Parameters:** * Inclination angle of AB: $\theta = 37^\circ$ * Length of horizontal conveyor belt CD: L = 3m * Vertical distance from A to the level of BC/CD: h = 2.4m * Height of the end of the conveyor belt (D) above the water surface (E): H = 0.8m * Kinetic friction coefficient between the cushion and AB slide: $\mu_1 = 0.5$ * Kinetic friction coefficient between the cushion and the conveyor belt: $\mu_2 = 0.2$ * Mass of the challenger: m = 50kg * Mass of the cushion: negligible * sin37° = 0.6 * cos37° = 0.8 * Acceleration due to gravity: g = 10m/s² **Diagram Description:** * **Type:** Schematic diagram illustrating a physics problem scenario. * **Elements:** * **Points:** Labeled points A, B, C, D, E. * **Lines/Paths:** * Inclined straight line AB, representing a slide, starts from point A and goes down to point B. * Horizontal line segment BC, representing a smooth transition. * Horizontal line segment CD, representing a conveyor belt of length L. * A dashed curved line starting from D and ending at E, representing the projectile motion path. * Dashed horizontal lines are used to indicate heights and levels. * A curved line at E represents the water surface. * **Angles:** An angle $\theta = 37^\circ$ is shown between the inclined line AB and a horizontal dashed line extending from B. * **Lengths/Heights:** * A vertical dashed line segment with label h=2.4m is shown from point A down to the horizontal level of BC/CD. * A horizontal double-headed arrow below CD is labeled L=3m. * A vertical dashed line segment from D down to the water surface at E is labeled H=0.8m. * **Objects:** A small figure (representing the challenger) is shown at point A on the slide. The segments BC and CD represent the transition and conveyor belt. The curve at E represents the water. * **Labels:** Points A, B, C, D, E are labeled. Dimensions h, L, H, and the angle $37^\circ$ are labeled with their values. * **Relative Position and Direction:** A is higher than BC/CD. BC and CD are horizontal. D is above the water surface E. The path from A to B is downwards along an incline. The path from D to E is a downward curve (projectile).