Train Problem set
Train Problems : āĻā§ā§°ā§āĻāĻ¨ āĻ¸āĻŽāĻ¸ā§āĻ¯āĻž
1. Train Crossing a Pole or Person
When a train crosses a pole or a person, the distance travelled equals the length of the train, because the pole or person has no length.
āĻ¯ā§āĻ¤āĻŋāĻ¯āĻŧāĻž āĻāĻāĻž āĻā§ā§°ā§āĻāĻ¨ā§ āĻā§āĻāĻāĻŋ āĻŦāĻž āĻŽāĻžāĻ¨ā§āĻš āĻĒāĻžā§° āĻā§°ā§, āĻ¤ā§āĻ¤āĻŋāĻ¯āĻŧāĻž āĻ āĻ¤āĻŋāĻā§ā§°āĻŽ āĻā§°āĻž āĻĻā§ā§°āĻ¤ā§āĻŦ = āĻā§ā§°ā§āĻāĻ¨ā§° āĻĻā§ā§°ā§āĻā§āĻ¯ āĻšāĻ¯āĻŧ, āĻāĻžā§°āĻŖ āĻā§āĻāĻāĻŋ āĻŦāĻž āĻŽāĻžāĻ¨ā§āĻšā§° āĻ¨āĻŋāĻāĻž āĻĻā§ā§°ā§āĻā§āĻ¯ āĻ¨āĻžāĻĨāĻžāĻā§āĨ¤
Formula: Speed = Distance / Time, Distance = Length of Train
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Q. A train 200 m long crosses a pole in 10 seconds. : āĻāĻāĻž ā§¨ā§Ļā§Ļ āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāĻ˛ āĻā§ā§°ā§āĻāĻ¨ āĻ āĻāĻāĻž āĻā§āĻāĻāĻŋ ā§§ā§Ļ āĻā§āĻā§āĻŖā§āĻĄāĻ¤ āĻĒāĻžā§° āĻā§°ā§āĨ¤
Distance āĻĻā§ā§°āĻ¤ā§āĻŦ= 200 m, : āĻĻā§ā§°āĻ¤ā§āĻŦ = ā§¨ā§Ļā§Ļ āĻŽāĻŋāĻāĻžā§°
Time = 10 s, āĻ¸āĻŽāĻ¯āĻŧ = ā§§ā§Ļ āĻā§āĻā§āĻŖā§āĻĄ
Speed = 200 ÷ 10 = 20 m/s
Convert m/s to km/h: 20 x 18/5 = 72
Speed : km/h āĻ¤ = 72 km/h, Note: m/s - km/h multiply by 18/5.
Q. Train length : āĻā§ā§°ā§āĻāĻ¨ā§° āĻĻā§ā§°ā§āĻā§āĻ¯ = 150 m(ā§§ā§Ģā§Ļ āĻŽāĻŋāĻāĻžā§°), Platform length : āĻĒā§āĻ˛āĻžāĻāĻĢā§°ā§āĻŽā§° āĻĻā§ā§°ā§āĻā§āĻ¯ = 100 m(ā§§ā§Ļā§Ļ āĻŽāĻŋāĻāĻžā§°) :
- Total distance : āĻŽā§āĻ āĻĻā§ā§°āĻ¤ā§āĻŦ = 150 + 100 = 250 m
Exam Tricks :
- Crossing pole/person → Distance = Train length : āĻā§āĻāĻāĻŋ āĻŦāĻž āĻŽāĻžāĻ¨ā§āĻš āĻĒāĻžā§° → āĻĻā§ā§°āĻ¤ā§āĻŦ = āĻā§ā§°ā§āĻāĻ¨ā§° āĻĻā§ā§°ā§āĻā§āĻ¯
- Crossing platform → Distance = Train + Platform : āĻĒā§āĻ˛āĻžāĻāĻĢā§°ā§āĻŽ āĻĒāĻžā§° → āĻĻā§ā§°āĻ¤ā§āĻŦ = āĻā§ā§°ā§āĻāĻ¨ + āĻĒā§āĻ˛āĻžāĻāĻĢā§°ā§āĻŽ
- Always check unit conversion : āĻ¸āĻĻāĻžāĻ¯āĻŧ āĻāĻāĻ āĻĒā§°āĻŋāĻŦā§°ā§āĻ¤āĻ¨ āĻāĻžāĻŦ āĻ˛āĻžāĻ