Problemas matemáticos e raciocínio lógico · Rate & Distance Models
Simulador de trem no túnel e movimento relativo
Simulador de movimento relativo e travessia de trens em túneis e pontes
- No navegador
- Sem cadastro
- Dedução ao vivo
- Modo projetor
- Folha de exercícios A4
Janela de demonstração matemática● 60 FPS
Variáveis de controle do experimento
m
m
m/s
m/s
Deduções e métricas em tempo real
Distância total percorrida
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Duração total t
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Velocidade equivalente
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Fase do movimento
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Dedução de fórmulas em tempo real
Fórmula fundamental:
--Substituição de valores:
--Conclusão: --
Exemplos clássicos e armadilhas de exame
Worked Problem
Problema: A 150m train travels at 15m/s over a 750m bridge. From head entering to tail leaving, how long does it take?
Derivação passo a passo:
- Distance S = bridge + train = 750 + 150 = 900m. Duration t = 900 / 15 = 60 seconds (1 minute).
Worked Problem
Problema: Train A (200m at 20m/s) and Train B (160m at 16m/s) travel toward each other. How long to pass each other completely?
Derivação passo a passo:
- Relative distance S = 200 + 160 = 360m. Relative speed v = 20 + 16 = 36m/s. Passing time t = 360 / 36 = 10s.
Folha de investigação em aula e exercícios
Q1. Variant 1: An 180m train crosses a 540m bridge in 36s. At the same speed, it passes a tunnel in 20s. Find tunnel length.
Answer Key: Train speed v = (540+180)/36 = 20m/s. Tunnel traversal S2 = 20*20 = 400m. Tunnel length = 400 - 180 = 220m.
Q2. Variant 2: A stationary bystander sees a 240m train pass him in 8s. What is the train speed?
Answer Key: The bystander is a point. Distance equals train length alone: S = 240m. Speed v = 240 / 8 = 30m/s (108 km/h).
Q3. Variant 3: Fast train (150m at 25m/s) overtakes slow train (250m at 15m/s) on parallel tracks. How long to clear?
Answer Key: Overtaking distance S = 150 + 250 = 400m. Relative speed = 25 - 15 = 10m/s. Overtake time t = 400 / 10 = 40s.
Perguntas frequentes e erros comuns
What is the #1 mistake elementary kids make in train bridge problems?
Treating the train as a dimensionless point and dividing bridge length directly by speed! An animation makes it visual: crossing is complete only when the rear clears.
Why is distance "tunnel minus train" when fully hidden inside?
The hidden interval starts when the rear enters the tunnel and ends when the head reaches the exit, spanning Tunnel Length - Train Length.
How to quickly convert upstream and downstream boat river speeds?
Downstream = boat + stream; Upstream = boat - stream. Quiet boat speed = (Down + Up) / 2. Stream speed = (Down - Up) / 2.
How to instantly solve the dog running back and forth between two approaching walkers?
Do not sum infinite geometric bounces! By simultaneity, the dog runs for the exact duration until the walkers meet (t = Dist / (v1+v2)). Dog distance = dog speed * t.