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英文数学(速度,一定要快)

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英文数学(速度,一定要快)
The braking distance(d metres)of a truck is proportional to the square of its speed(Vkm/h).If d =10,when v=36,calculate
(a) d when v = 60
(b)v when d=144
帮忙做出并要有过程和解释
原题目:刹车距离与速度平方成正比,当d=10时V=36 (a)当V=60时,求d
(b)当d=144时,求V
解题步骤:设方程为d=kV²,将d=10,v=36带入可解得k=10/(36*36)
(a)将v=60带入原方程得d=250/9
(b)将d=144带入原方程得V²=144*36*36/10则v=(432√10)/10 (其中√为根号)
再问: 嗯,谢谢,再帮我回答一个就给分 a photocopier enlarges by a ratio of 7:4. A picture measures 6cm by 4 cm.How many consecutive enlargements can be made so that the largest possible picture will fit on a sheet measuring 30 cm by 20 cm? 帮我翻译,还有解答过程和解释