In ａ certain instance, a plane flying horizontally was at a distance 5000m vertically above timmy's head.Atfer 10 seconds, it was 6000m from timmy's head. What was the speed of the plane in km/ｈ?
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2007-12-03 4:45 am
回答 (2)
2007-12-03 4:56 am
✔ 最佳答案
distance travelled in 10 seconds = 6km 二次方 減 5km 二次方
= 開方11 km
speed of the plane in km/h
= 開方 11 乘 6 乘 60
= 1193.98 km/h
2007-12-03 6:19 am
Let x be the length travelled by the plane.
5000^2+x^2=6000^2 (pyth.thm.)
x^2=6000^2-5000^2
x=√(6000^2-5000^2) m
The speed of the plane
=[√(6000^2-5000^2)/1000] / 10 *3600
=1200 km/h (3 sig. fig.)
5000^2+x^2=6000^2 (pyth.thm.)
x^2=6000^2-5000^2
x=√(6000^2-5000^2) m
The speed of the plane
=[√(6000^2-5000^2)/1000] / 10 *3600
=1200 km/h (3 sig. fig.)
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