- #1

Chenkel

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- TL;DR Summary
- I'm watching a Walter Lewin lecture on rolling motion, and I notice he uses a frictional force to apply a torque to a cylinder and I'm wondering about the reasoning

Hello everyone!

I'm watching this Walter Lewin lecture and am at 5:58 part of the video

I'm wondering how there's a frictional torque applied to the cylinder, my reasoning is that the object has forward velocity, and on a perfect cylinder, the slope of the incline touches the cylinder at a line parallel to the length of the cylinder, this creates a torque, and the force that creates the torque is less than the kinetic frictional force, so the cylinder does not slide, I'm trying to figure out how this creates a clockwise rotation (why is the direction of the force that creates the torque uphill?), I'm wondering where my logic is correct, and hoping someone can fill in my knowledge gaps, if anyone has a break down of what's happening let me know, thank you!

I'm watching this Walter Lewin lecture and am at 5:58 part of the video

I'm wondering how there's a frictional torque applied to the cylinder, my reasoning is that the object has forward velocity, and on a perfect cylinder, the slope of the incline touches the cylinder at a line parallel to the length of the cylinder, this creates a torque, and the force that creates the torque is less than the kinetic frictional force, so the cylinder does not slide, I'm trying to figure out how this creates a clockwise rotation (why is the direction of the force that creates the torque uphill?), I'm wondering where my logic is correct, and hoping someone can fill in my knowledge gaps, if anyone has a break down of what's happening let me know, thank you!