(20 14? Suqian No.2 model) The driver will fly over a river with a width of D, and build a slope with a height of H and an inclination angle of α on the left side of the river bank.

A, according to the topic analysis, the movement of the car on the left slope is unknown, and the acceleration time t cannot be determined, so A is wrong.

B. the quality of the car is unknown. According to the kinetic energy expression Ek= 12mv2, it can be known that the kinetic energy Ek cannot be obtained when the car leaves the left slope. So, B is wrong.

C let the speed of the car leaving the left slope be v 1.

According to the uniform linear motion in the horizontal direction: d=v 1cosα? t…①

The vertical upward throwing action is Hm=(v 1sinα)22g…②.

With the vertical upward direction as the positive direction: -(h-H)=v 1sinα? t- 12gt 2③

Exercise time t and v 1 can be obtained from ② and ③, and the maximum height hm can be obtained from ②. So, C is correct.

D, according to the speed decomposition: tanα=vy 1vx, tanθ=vy2vx.

Since h > h and the vertical fractional velocity relation is vy 1 < vy2, α < θ, so d is correct.

So: CD.

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