What is the Maximum Speed and Travel Time for a Subway Train?

  • Thread starter Thread starter Kside
  • Start date Start date
  • Tags Tags
    Kinematics
AI Thread Summary
The discussion focuses on calculating the maximum speed and travel time for a subway train given specific parameters. The maximum acceleration tolerated by passengers is 1.54 m/s², and stations are 816 m apart. The user calculated the time to reach maximum speed as approximately 32.55 seconds and derived a maximum speed of about 50.13 m/s for part (a). The responses confirm that the calculations for part (a) are correct and encourage the user to apply the average speed formula for part (c). The thread emphasizes the importance of understanding the formulas for accurate calculations in physics.
Kside
Messages
1
Reaction score
0
I'm having a bit of trouble with this question and would greatly appreciate all the help I can get...

(a) If the maximum acceleration that is tolerable for passengers in a subway train is 1.54 m/s2 and subway stations are located 816 m apart, what is the maximum speed a subway train can attain between stations? (b) What is the travel time between stations? (c) If a subway train stops for 24.0 s at each station, what is the maximum average speed of the train, from one start-up to the next?

-I started (a) using the formula: x = vt + 1/2at^2
-I plugged in 816m for x and 1.54m/s^2 for a
-I got t=32.5537
-Then I used this time and the given acceleration to solve for v using the formula: a = v/t getting the answer 50.1326 for part (a)

Can someone please let me know if this is correct and how I can begin to tackle parts (b) and (c)?

Thanks!
 
Physics news on Phys.org
Assuming the train does not slow down when approaching the station , answer looks OK for 'a'.
For b, you already solved it!
For c, what's the formula for average speed.
 
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...
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...
Back
Top