(2012?Pudong New Area second model) as shown in the figure for a flat throw motion experimental device, let the ball from the sloping groove guide rail horizontal groove thrown, the use of placed in t

(2012?Pudong New Area second model) as shown in the figure for a flat throw motion experimental device, let the ball from the sloping groove guide rail horizontal groove thrown, the use of placed in the (1) the horizontal direction of the parabolic motion to do do uniform motion, x = v0t, so the landing point of the horizontal distance d and the initial velocity v0 is proportional to, so A is correct, B is wrong;

vertical direction of free-fall motion, h =

1

2

gt2, solving for: t=

2h g

, the flight time t0 has nothing to do with the size of the initial velocity v0, so C is wrong, D is correct.

Therefore, choose AD

(2) According to the meaning of the question: d=v0t=v0

2h g

If the ball's initial velocity becomes 1.25v0, then 1.25v0?

< td style="border-bottom:1px solid black">2h′ g

=v0

2h g

Solve: h′ = 0.64h

So the answer is: (1) AD; (2) 0.64