Torque and angular momentum with a central force

Thread starter fer Mnaj
Start date Aug 24, 2020
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Angular Angular momentum Central force Force Momentum Torque

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The discussion centers on the relationship between torque and angular momentum in the context of a central force. It is established that the torque equation τ = r ˆr x - k / r^2 ˆr equals zero since ˆr x ˆr is zero. The conversation then shifts to angular momentum, defined as L = r x p, indicating that without additional information, this is the complete expression for angular momentum. The participants agree that these fundamental equations are crucial for understanding motion under central forces. Overall, the thread highlights key principles of torque and angular momentum in physics.

Aug 24, 2020

fer Mnaj

Homework Statement: Consider the central force ##F (r) = - k / r^2 ˆr ## to which a particle of mass m is subject; where ˆr is the unit vector along the line connecting the center of forces with the position of the particle. Calculate the torque that F exerts on m and the angular momentum of the particle;
Calculate the torque that F exerts on m and the angular momentum of the particle;
both quantities with respect to O

Relevant Equations: τ= r x F L=rxp

HI

τ= r ˆr x - ##k / r ^ 2## ˆr= 0 right? since ˆr x ˆr is zero

What about L?

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Aug 24, 2020

BvU

Science Advisor

Homework Helper

As you say, ##\vec L = \vec r \times \vec p ## . If you have no further information, that's it.

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