須列式解釋!!
1.) The gradient of a road is 1:8. After walking 200m along the road,
what is the vertical distance travelled?
2.)Paul walks 100m towards east,then 140m towards north, and finally 80 m towards east. What is the whole circle bearing of his final position from his starting position ?
(Give the answer correct to the nearest degree.)
maths (中三)
2007-04-29 10:02 pm
回答 (1)
2007-04-29 10:34 pm
✔ 最佳答案
1.Let θ be the angle of the inclination of the road.
tanθ = 1/8
θ = 7.125゜
Let x m be the vertical distance travelled.
cos 7.125゜= x/200
x = 200 cos 7.125゜
= 198 (cor. to 3 sig. fig.)
∴The vertical distance travelled is 198 m.
2.
tanθ = 140/(100+80)
θ = 38゜
∴The whole circle bearing of his final position from his starting position is N52゜E.
(90゜- 38゜= 52゜)
收錄日期: 2021-04-23 14:09:19
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070429000051KK02365