Angular Momentum and Torque of a Moving Particle

AI Thread Summary
The discussion focuses on calculating the angular momentum and torque of a moving particle with given mass, position, and velocity. The participant initially struggled with applying the cross product to find the correct direction and magnitude of angular momentum and torque. They realized that simply using magnitudes without considering angles would not yield accurate results. After some guidance, they acknowledged the need to show their calculations for better feedback. The conversation emphasizes the importance of understanding vector operations in physics problems.
agargento
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Homework Statement



A 2.9-kg particle P is located at [(r)\vec] = 3.3 m [^(x)] + 1.8 m [^(y)] from the origin of the x-y coordinate system shown in the Figure. It moves with a velocity of [(v)\vec] = −4.1 m/s [^(x)] + 2.6 m/s [^(y)]. A force, [(F)\vec] = 2.7 N [^(x)] + 1.4 N [^(y)] acts on the particle.

a) What is the magnitude and direction of the angular momentum of the particle with respect to the origin of the coordinate system?
b) What is the magnitude and direction of the torque acting on the particle with respect to the origin of the coordinate system?

‏‏לכידה.PNG


Homework Equations



L = r x mv
T = r x F

The Attempt at a Solution



At first I tried to take the magnitude of the radius r, the mangitude of v, and multiply by the mass. But this doesn't give me the direction... I also tried taking the cross product but it didn't go well, I got confused with the direction and the multiplication... would love some guidance.

Edit: Got the answer. Sorry for littering the forum ;)
 
Last edited:
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agargento said:
At first I tried to take the magnitude of the radius r, the mangitude of v, and multiply by the mass. But this doesn't give me the direction...
It also won't give you the correct magnitude if you ignored the angle between the vectors...
agargento said:
I also tried taking the cross product but it didn't go well, I got confused with the direction and the multiplication...
Show the details of your attempt using the cross product method. We can't critique what we can't see :smile:
 
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