Xuzhou ding information consultation

After the (1) ball is thrown, its motion law satisfies x=vt, y= 12gt2, which has nothing to do with the ball quality, so we don't choose f: balance. In the experiment, we eliminated T in the calculation process by drawing the trajectory, so I: stopwatch is not needed.

(2) Answer: In order to ensure that the ball is thrown flat, the end of the chute track is horizontal. A is correct.

B: In order to ensure the ball to do the same flat throwing motion, the ball should slide down from the same position on the slideway. B error.

C: When the ball leaves the chute, it should be thrown horizontally, so there is no need to balance the friction. C error.

D: In order to ensure that the ball makes the same flat throw every time, the ball should slide down from the same position on the slide. D is correct.

So choose ad.

(3) The ball moves in a straight line at a uniform speed in the horizontal direction and falls freely in the vertical direction. If the horizontal displacement intervals of points A, B and C are equal and the time is equal, the ratio of vertical displacement intervals should be 1: 3: 5, and the vertical position coordinate corresponding to point B is 20. So the position of point B is wrong.

According to h= 12gt2 and t = 2hg = 2× 0.45 10s = 0.3s, the initial velocity v0 = XT = 0.30.3m/s =1.0m/s. 。

So the answer is: (1)F, I (2)AD (3)B? 1.0.