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5. True or False, a tire has a diameter of 31 inches. Steven said it will roll 390.50 inches if it makes 4 revolutions?​

User Rofer
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1 Answer

5 votes

Answer: False

Step-by-step explanation:

Let's find the circumference of the tire

C = pi*d

C = 3.14*31

C = 97.34

The perimeter of the tire is about 97.34 inches.

When the tire does 1 revolution, the car moves forward about 97.34 inches. This is because the tire will roll around the edge, i.e. move along the perimeter.

In four revolutions, it rolls forward about 4*97.34 = 389.36 inches.

If you used the calculator's stored value of pi, then the answer is about 4*31pi = 389.5575

This is close to 390.50, but not quite there. It's not clear what steps or calculations Steven did to get his answer.

User Crauscher
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