2.On a particular railway,a train driverapplies the brake of the train at a yellow signal,a distance of 1.0km from ared signal,where it stops.The maximum deceleration of the train is 0.2ms–2.Assuming uniform deceleration,what is themaximum safe spe

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/06 04:20:22
2.On a particular railway,a train driverapplies the brake of the train at a yellow signal,a distance of 1.0km from ared signal,where it stops.The maximum deceleration of the train is 0.2ms–2.Assuming uniform deceleration,what is themaximum safe spe
xTMOA+sZw*n G)SC]eXV1QcbGmY<\Q1Gӹ 57 !&#?7K

2.On a particular railway,a train driverapplies the brake of the train at a yellow signal,a distance of 1.0km from ared signal,where it stops.The maximum deceleration of the train is 0.2ms–2.Assuming uniform deceleration,what is themaximum safe spe
2.On a particular railway,a train driverapplies the brake of the train at a yellow signal,a distance of 1.0km from ared signal,where it stops.The maximum deceleration of the train is 0.2ms–2.
Assuming uniform deceleration,what is themaximum safe speed of the train at the yellow signal?
A.20m/s
B.40m/s
C.200m/s
D.400m/s
E.100m/s

2.On a particular railway,a train driverapplies the brake of the train at a yellow signal,a distance of 1.0km from ared signal,where it stops.The maximum deceleration of the train is 0.2ms–2.Assuming uniform deceleration,what is themaximum safe spe
A
题目说看到信号后要在1km之内停下,火车的最大加速度为0.2m/s^2,问火车的安全速度是多少
v^2=2as=2*0.2*1000(m/s)^2=400(m/s)^2
v=20m/s

选A
楼主原文有个地方打错了,最大减速度的单位应该是米每二次方秒。
由公式1/2at*t=1000,算出最大减速度时用的时间t=100秒
由公式1/2vt=1000,算出最大速度v=20米每秒。

Assume V0 is the speed at the yellow signal. apparently the speed at the red signal is 0.
The time for train moving from yellow to red T=(V0-0)/0.2=0.2V0.
Then 0.5(V0+0)*0.2V0=1000;
Thus,V0=100m/s, which is the maximum safe speed.

可以

英语翻译There’s also case study research where again you can look at a particular case with a view to getting a particular handle on a particular phenomenon. a ra ta 英语questionin a particular afternoon my mother brought the drink in改错题为什么上面是in a particular afternoon my mother brought the drink on谢谢 英译中2句This gird in the row stands for betting on a particular horse which runs at the first place.This gird in the column stands for betting on a particular horse which runs at the second place. 英语翻译there's not a men here who does not look down on one particular breed of humanity I am usually very busy,and on weekends__.A.in particular B.in fact C.in turn D.in need 英语语言学2.Natural languages are viewed to vary according to____ set on UG principles to particular values. A Adjacent Condition B parameters C Case Condition D Case requirement 英语翻译This article focuses on the problem of a particular type of service and the barriers on this service (express delivery) that countries place upon it. a particular british celebration全文翻译 a particular time when sth happens. a particular moment 怎么翻译好 Old memories are often()when you hear a particular song or a piece of music.A,called in B.called on C,called out D,called up -on this particular day,I miss you more. ()is particular for VIP on the opening ceremony of the festival.A.Platform Eight B.The Platform Eight C.The Eight Platform D.Eight Platform说明原因 ---The experiment is of particular importance.---I see.We’ll carry on with it ______ we can get enough money.A.until B.unless C.whether D.however 英语翻译In our core line of business of photovoltaics in particular,proximity to our customers and a clear focus on quality pay off. 英语翻译Establishing leakage rate specifications early during product development passed on the particular product and package performance characteristics to ensure product will reflect these limits is a must. He didn't go into detail on that subject.He spoke ___.A.in general B.in particular C.in common D.in short