Rotational motion, frictionless.

by azizlwl
Tags: frictionless, motion, rotational
azizlwl is offline
May5-12, 05:57 AM
P: 961

A rope is wound around a cylinder of mass 4kg, and I=0.02kg.m2 about the cylinder axis.
The frictional force between table and cylinder is negligible.

α=ar is not applicable when slippage occurs.

My question.
1.Is the cylinder moves forward with acceleration a without any rotation.
2. Is Fr=Iα is still applicable in this case, even though we know α=ar not applicable.
3. If we play yo-yo in zero gravity environment,how does the yo-yo behave when we pull it?

Thank you.
Phys.Org News Partner Physics news on
Physicists design quantum switches which can be activated by single photons
'Dressed' laser aimed at clouds may be key to inducing rain, lightning
Higher-order nonlinear optical processes observed using the SACLA X-ray free-electron laser
K^2 is offline
May5-12, 06:14 AM
Sci Advisor
P: 2,470
1. No, see 2.
2. Yes, Fr=Iα is always applicable. α=ar constraint is only needed for rolling, and is achieved via additional force, that being the force of friction. When no friction is present, you just compute angular and linear accelerations separately.
3. Yo-yo in zero-g will behave exactly the same as this test case. It will accelerate and spin in direction it's being pulled.
azizlwl is offline
May5-12, 06:21 AM
P: 961
Thank you.
That really helpful since the book didn't say about rotation only a=αr is not applicable.

haruspex is offline
May6-12, 07:21 PM
Sci Advisor
HW Helper
Thanks ∞
P: 9,159

Rotational motion, frictionless.

A nice question to ask here is to find the instantaneous centre of rotation.

Register to reply

Related Discussions
Frictionless half-pipe and rotational motion question Advanced Physics Homework 35
Rotational Motion change angular rotational Introductory Physics Homework 3
Rotational Motion: Rotational vs. translational kinetic energy General Physics 3
Rotational Motion & Rotational Kinetic Energy Introductory Physics Homework 5
Frictionless Rolling Motion General Physics 20