infamous question 4! (1 Viewer)

[coolboy234]

4. A car follows another car along a straight stretch of an open highway at 100 kilometres per hour. The cars are 150m apart. The cars approach a town. When each car reaches the town it slows down at the same rate to 30 kilometres per hour. Both cars travel through the town at 30 kilometres per hour.
How far apart will the cars be when they are both travelling at 30 kilometres per hour?

there it is, CAN YOU SOLVE IT???







thanks in advance, coolboy234

 

[bored of sc]

You have posts EVERYWHERE.

Here's my working to this question.

Time between cars: distance/speed = m/m/s = s

100km/h = 27.77777... m/s (100 divide 3.6)

Time between cars = 150/27.777777 = 5.4 s

Therefore it will take car 2 5.4 seconds to get the 30km/h zone car 1 is travelling in.

So now find the distance car 1 will travel in the 30km/h zone in 5.4 seconds and that's the answer.

Distance = speed x time = m/s x s = m
distance = 8.33333 m/s (30/3.6) x 5.4

= 45m

Ahhhh! This answer is different to the other one I posted.

 

[Aerath]

Ahhhh! This answer is different to the other one I posted.

Hahaha, way to confuse him.

 

[bored of sc]

Come on Maths whiz kids. Where are you? This question should be a doozy for yous.

 

[kony]

If the two cars have undergone the same motion at the same time, the distance between them will never change.

Therefore, 150m.

edit: misread the question.

 

[bored of sc]

If the two cars have undergone the same motion at the same time, the distance between them will never change.

Therefore, 150m.

But car 1 slows to 30km/h as car 2 still goes 100km/h till it reaches the town. That means car 2 will move closer in distance to car 1.

 

[bored of sc]

hey bored of sc, ur explanation is right, but which is the solution that is right, the 50m or the 45m?

I'm 95% sure 45m is right. I thought you would have had the answers... What are the questions for by the way --> holiday homework?

 

[coolboy234]

I'm 95% sure 45m is right. I thought you would have had the answers... What are the questions for by the way --> holiday homework?

yeah, 45m is right, i just found the answers. your a genius, bored of sc!!! anywayz it must be right because in the time that it takes for car 2 (5.4 seconds) to clear the 150m distance between the two cars, the 5.4 seconds in which the 1st car travels at 30km/hr must be the final distance between them, so you were right.







thanks again, coolboy234

 

[lolokay]

4. A car follows another car along a straight stretch of an open highway at 100 kilometres per hour. The cars are 150m apart. The cars approach a town. When each car reaches the town it slows down at the same rate to 30 kilometres per hour. Both cars travel through the town at 30 kilometres per hour.
How far apart will the cars be when they are both travelling at 30 kilometres per hour?

there it is, CAN YOU SOLVE IT???







thanks in advance, coolboy234

in the time it takes a car to travel 150m at 100km/h, a car travelling at 30km/h will have travelled 30/100 times that distance.. so 45

 

[bored of sc]

in the time it takes a car to travel 150m at 100km/h, a car travelling at 30km/h will have travelled 30/100 times that distance.. so 45

Oh! Way to show me up.

 

[lolokay]

Oh! Way to show me up.