(20 14? Xinyu simulation) as shown in the figure, the measurement shows that the length of the equal arm seesaw AB is 6m(OA=OB), and the height of the supporting point O from the ground is 0.78m When

(20 14? Xinyu simulation) as shown in the figure, the measurement shows that the length of the equal arm seesaw AB is 6m(OA=OB), and the height of the supporting point O from the ground is 0.78m When it Solution: solution: (1)OA=OB= 12AB=3m,

sin∠ABC=OHOB=0.26，

The degree of α is15;

(2) Take point A as AD⊥BC, and pass through the extension line of BC at point D to connect OD.

According to the problem, when A touches the ground, the angle of AO is 30.

Therefore, the route length of point A is π× 3× 30180 =1.6m. 。

Therefore, the movement route length of point A is about1.6m; ;