- Asked 3/16
- 2079 Bhadra · 8 marks
Schedule speed for a 1.5 km run (trapezoidal)
Short answer
Using the trapezoidal relation 3600D=VmT-(Vm^2/2)K with K=1/0.8+1/3.2=1.5625 and Vm/Va=1.3, solve Vm=45.54 km/h, running time 154.16 s. Total time with 26 s stop is 180.16 s, schedule speed=(1.5×3600)/180.16=29.97 km/h (≈30 km/h).
An electric train is to have acceleration and braking retardation of 0.8 km/h/s and 3.2 km/h/s respectively. If the ratio of maximum to average speed is 1.3 and time for stops 26 seconds, find the schedule speed for a run of 1.5 km. Assume simplified trapezoidal speed-time curve.
Data: km/h/s, km/h/s, , km, stop s.
Trapezoidal relation (speeds in km/h, time in s)
Since and : .
Running time and schedule speed
Check: s, s, free running s.
Answer: Schedule speed ≈ 29.97 km/h (≈ 30 km/h); maximum speed 45.5 km/h.
✓ Answer checked by Claude Opus 5.5 (high effort)
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