英语翻译You are planning a bicycle trip for which you want to average 24km/h.You cover the first half of the trip at an average speed of 21km/h.What must your average speed be in the second half of the trip to meet your goal?
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英语翻译You are planning a bicycle trip for which you want to average 24km/h.You cover the first half of the trip at an average speed of 21km/h.What must your average speed be in the second half of the trip to meet your goal?
英语翻译
You are planning a bicycle trip for which you want to average 24km/h.You cover the first half of the trip at an average speed of 21km/h.What must your average speed be in the second half of the trip to meet your goal?
英语翻译You are planning a bicycle trip for which you want to average 24km/h.You cover the first half of the trip at an average speed of 21km/h.What must your average speed be in the second half of the trip to meet your goal?
1.以路程为等量S=24t(T1+T2)
S=21*T1+V2*T2,又S=1/2S+1/2S→→21*T1=V2*T2→→T1=V2*T2/21
所以24t(T1+T2)=21*T1+V2*T2→→3*T1=(V2-24)T2
3*（V2*T2/21)=(V2-24)T2→→3*V2/21=V2-24
V2=28km/h
2.以时间为等量
(S/2)/21 + (S/2)/v2 = S/24
∴ v2 = 28 km/h
因为不会打脚标因此把各个量如SVT本应该是小写的改成大写了,楼主书写的时候可以改成小写的,并把→根据逻辑关系改成∵和∴
24*2-21=27真的那么简单？？？？而且还有单位的那些呢？？？我国外的，但老师是中国人，严格死了你准备骑自行车以24公里每小时的平均速度去旅游，前半个旅程的平均速度只有21公里每小时。那么后半个旅程你的平均速度要达到多少才能满足整个旅程的要求呢？ 24/（2-24/21）=24*21/18=28（km/h） 上式的说明：假设一共有两小时的路程即24*2=48公里 那么，走了一半用时为24...
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24*2-21=27
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自行车比赛要求平均速度达到24KM/h。前半圈平均速度是21KM/h，后半圈平均速度应该是多少？
24X2-21=27。没错！
要注意物理意义：平均速度的含义并不是速度的平均值。
列方程应为：
(S/2)/v1 + (S/2)/v2 = S/v
即 (S/2)/21 + (S/2)/v2 = S/24
求出
v2 = 28 km/h