4 ms·
I think you can always arrive at the correct answer by tracking the distance traveled by the center of the rolling object. In the original SAT question, the ce
by icegreentea2 3y ago
I think you can always arrive at the correct answer by tracking the distance traveled by the center of the rolling object.
In the original SAT question, the center of the rolling circle is 4r from the center. That means it travels an arc of 8pi. Then assuming no-slip, that works out to 4 rotation.
In your case, rolling on the inside, the center of the rolling circle will only be 2r from the center. Using the same logic, this yields 2 rotations.
- bearmode 3y agoThis is definitely the easier way to understand it. Imagine a point in the centre of the circle that is traveling. Draw the line that point takes, and then calculate using the new circle.
- HarHarVeryFunny 3y agoYes - the relationship between distance traveled by center and number of rotations (= distance/diameter) is a nice generalization, although the guy in the video went so fast that I didn't understand his derivation of this relationship (related to speed, etc).