Solving Train Collision: Min Rate, Collision Speed & Distance Traveled

  • Thread starter Thread starter ts21121
  • Start date Start date
  • Tags Tags
    Collision Train
AI Thread Summary
A passenger train traveling at 30 m/s must decelerate at a minimum rate of 0.887 m/s² to avoid colliding with a freight train 336 m ahead, which is moving at 5.9 m/s, given a reaction time of 0.36 seconds. For a longer reaction time of 0.79 seconds, the passenger train's approach rate to the freight train at the moment of collision needs to be calculated. The equations of motion provided will help determine the distance traveled by the passenger train during the time from sighting the freight train to collision. The discussion highlights the importance of accurate calculations in determining safe stopping distances and speeds. Further clarification on calculations is requested to resolve discrepancies in the answers.
ts21121
Messages
3
Reaction score
0
A passenger train is traveling at 30 m/s when the engineer sees a freight train 336 m ahead of his train traveling in the same direction on the same track. The freight train is moving at a speed of 5.9 m/s.

1.If the reaction time of the engineer is 0.36 s, what is the minimum (constant) rate at which the passenger train must lose speed if a collision is to be avoided?

2. If the engineer's reaction time is 0.79 s and the train loses speed at the minimum rate described in Part (a), at what rate is the passenger train approaching the freight train when the two collide?


For both reaction times, how far will the passenger train have traveled in the time between the sighting of the freight train and the collision?

x=x0+v0t +1/2 at2
v=v0+at



The Attempt at a Solution


for part 1 i know the answer is .887m/s^2.
after this i am completely lost on how to solve for part 2 and 3
 
Physics news on Phys.org
Hi ts21121, welcome to PF.
I am getting slightly different answer for the part 1. Will you show your calculations?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

1-dimensional kinematics - final velocity of 2 trains in opposing direction
Replies
3
Views
802
Train collision (linear kinematics)
Replies
6
Views
2K
Kinematics involving two objects
Replies
3
Views
2K
A passenger train is traveling at 27 m/s when the engineer s
Replies
4
Views
2K
Deceleration necessary to prevent a train collision
Replies
2
Views
2K
Deceleration of Train to Avoid Collision
Replies
1
Views
4K
Train Collision Problem - Calculating Head Start
Replies
1
Views
4K
AP Physics 1 kinematics problem
Replies
1
Views
2K
Two decelerating trains on a collision course
Replies
2
Views
2K
Train chase: collision avoidance
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top