(Old) Axle Roads

How do vehicles turn so smoothly?

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(Old) Axle Roads

How do vehicles turn so smoothly?

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A newer, better version of this lesson is available! Explore all updated lessons here, or read more about the updates in Our Community.

2023-2024 Versions

In the fall of 2024, Citizen Math released updated versions of every lesson in our library, plus a few new ones! We know you may have already prepped an earlier version or planned a repeat of last year, so we're continuing to make these earlier versions available through Thursday December 5, 2024.

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How do vehicles turn so smoothly? When a car makes a U-turn, the outer wheel travels farther than does the inner wheel. So why doesn’t the car feel jerky?

In this lesson, students calculate the circumferences of circles to determine how far vehicles travel during a turn and explore the engineering that allows cars to turn so smoothly.

REAL WORLD TAKEAWAYS

  • A turning radius describes the smallest circle a car can make. The smaller the radius, the tighter the turn.
  • Left and right car wheels have to cover different distances – and thus rotate different numbers of times – when turning. A differential axle allows this to happen.

MATH OBJECTIVES

  • Calculate the circumference of a circle
  • Model with geometry to solve real-world problems

Appropriate most times as students are developing conceptual understanding.
Grade 7
Measuring Circles
Grade 7
Measuring Circles
Content Standards
Mathematical Practices

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