Physics 100: Solving the Overtaking Problem of a Car and Train

[alda00]

I have a homework problem that I can't solve, I have been spending some time on it. It goes like this...

An automobile traveling 95km/ overtakes a 1.10 km long train traveling i the same direction on a track parallel to the road. If the train's speed is 75kh/h how long does it take for the car to pass it, and how far will the care have traveled in this time?

 

[rootX]

I have a homework problem that I can't solve, I have been spending some time on it. It goes like this...

An automobile traveling 95km/ overtakes a 1.10 km long train traveling i the same direction on a track parallel to the road. If the train's speed is 75kh/h how long does it take for the car to pass it, and how far will the care have traveled in this time?

you must show your work, first.

try considering this question:
An automobile traveling 95 km/hr is 1.10 km behind a train(a point source) that is traveling at 75 km/hr, and so how long does it takes...?

 

[mjsd]

always draw a diagram if in doubt

 

[B-80]

remember that all motion is relative so think of the way the car is moving relative to the train, so how long would it take?

 

[mjsd]

by the way, with that sort of speed, I don't think it is a question involving special relativity either, so standard Newtonian mechanics and Galilean relativity are applicable

 

[cks]

Denote the position of the front part of the train as y

y=75t+1.10

Denote the position of the car as

x=95t

You can see the logic of the equations above, at time t = 0, y=1.10km (correct!)
At time t=0, x=0(correct)

with the derived equations of the positions of the train and car, and for the car to overtake the train, their position have to be the same at a certain time t, so, what should you do?