Current location - Training Enrollment Network - Mathematics courses - [Urgent] Senior High School Entrance Examination Answer: 20 12 Changchun Mathematics Senior High School Entrance Examination Question 26 Answer
[Urgent] Senior High School Entrance Examination Answer: 20 12 Changchun Mathematics Senior High School Entrance Examination Question 26 Answer
It is easy to know that when ND coincides, t=4s, and let t seconds h fall on CD.

At this time, MH/CM=tan angle DCA=tanA=0.5.

When (1)H is from m to n, there is MH/CM=(2.5T)/(4-T)=0.5, and the solution is T=2/3. At this time t= 14/3s.

(2) When h is from n to m, there is MH/CM=(2-(2.5T-2))/(4-T), and the solution is T= 1, at which time t=5s.

(3) When h goes from m to n again, there is MH/CM=(2.5T-4)/(4-T), and the solution is T=2, at which time t = 6s, and p and e coincide.

(4) When P is on BE, MH/CM is always 0.5, that is, H is always on CD, and at this time, 6≤t≤8.

To sum up, when t= 14/3 or t=5 or 6≤t≤8, H falls on the CD.

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