Ah! It's dangerous.

Peter puts a board on top of a wheel, as shown. He pushes the board so that the wheel rolls without slipping. If the wheel moves by a distance of 2 m, what is the distance Peter moves?

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2 solutions

If the tire rotate n n times, then the board will move n × circumference n\times\text{circumference} relative to the tire. But the tire will move also. If the board move l l relative to the tire, then the tire will move l l also. So if the tire move l l , then the board will move l + n × circumference l+n\times\text{circumference} . but l = circumference × n l=\text{circumference}\times n . Therefore the board will move 2 × 2\times more than the tire. Therefore the solution is 2 × 2 m = 4 m 2\times2m=4m .

Very simple problem, it only requires logic and practicality :)

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No. Only logic

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nice animation

SRIJAN Singh - 10 months ago

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@Srijan Singh thank you! some text

That means my logic is bad, I got it wrong

Vinayak Srivastava - 9 months, 4 weeks ago

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@Vinayak Srivastava you're good

SRIJAN Singh - 9 months, 3 weeks ago
Chew-Seong Cheong
Aug 15, 2020

For easy visualization, assume Peter starts at the end of the board exactly on top of the center of the wheel as shown in the top figure. As Peter pushes forward and the wheel rotates without slipping, the wheel moves relative to the ground 2 m \text{ 2 m} forward. Because there is no slipping the wheel also moves relative to the board 2 m \text{2 m} forward. Therefore, the distance the board moves forward relative to the ground is 2 + 2 = 4 m 2 + 2 = \text{4 m} . Since Peter is holding the board, Peter also moves forward 4 m \boxed 4 \text{ m} .

thanks sir,I can't express my feelings for you for answering my questions @Chew-Seong Cheong thanks for editing

SRIJAN Singh - 10 months ago

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I have also change "tire" to a "wheel". Because the image does not look like a tire but I wheel and I don't want to edit the image.

Chew-Seong Cheong - 10 months ago

Please don't use all caps in writing. It means that you are shouting. Which is very rude. I edited the problem for you, including turning PETER to Peter. Also the title. Not all lower case. Just use normal English style.

Chew-Seong Cheong - 10 months ago

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okay . i was not aware

SRIJAN Singh - 10 months ago

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