Passing Trains

TL;DR

Train A and Train B pass each other in different directions, taking 15 seconds when moving in the same direction and 5 seconds when moving in opposite directions. Find the velocity of each train in meters per second.

Transcript

This is the fourth of the five problems that Kortaggio sent me today. And I've been doing these problems because I think they're really neat applications of essentially fairly basic, even you could call it physics, rate problems, and a little bit of algebra. But you're able to figure out pretty neat things, where you're not sure if there's enough i... Read More

Key Insights

• 🚂 The problem involves finding the velocity of Train A and Train B.
• 🤒 Train A is 200 meters long and Train B is 400 meters long.
• 🚄 When moving in the same direction, Train A passes Train B in 15 seconds.
• 🚂 When moving in opposite directions, Train A and Train B pass each other in 5 seconds.
• 🚂 The relative velocity of Train A to Train B is the difference between their individual velocities.
• 🚄 By setting up equations and making assumptions about reference points, the velocities of Train A and Train B can be determined.
• 🤒 The velocity of Train A is 80 meters per second and the velocity of Train B is 40 meters per second.

Questions & Answers

Q: How long does it take for Train A to pass Train B when moving in the same direction?

It takes 15 seconds for Train A to pass Train B when moving in the same direction.

Q: How long does it take for Train A and Train B to pass each other when moving in opposite directions?

It takes 5 seconds for Train A and Train B to pass each other when moving in opposite directions.

Q: What are the lengths of Train A and Train B?

Train A is 200 meters long and Train B is 400 meters long.

Q: How can we find the velocity of each train?

By assuming a reference point in the green train and using the relative velocities, we can set up equations to solve for the velocity of Train A and Train B.

Summary & Key Takeaways

• Train A is 200 meters long and Train B is 400 meters long.

• When moving in the same direction, Train A passes Train B in 15 seconds.

• When moving in opposite directions, Train A and Train B pass each other in 5 seconds.