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ChazyChazLive
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Homework Statement
At the instant of Fig. 11-42, a 6.60 kg particle P has a position vector [tex]\stackrel{\rightarrow}{r}[/tex] of magnitude 3.80 m and angle θ1 = 42.0° and a velocity vector [tex]\stackrel{\rightarrow}{v}[/tex] of magnitude 9.70 m/s and angle θ2 = 33.0°. Force [tex]\stackrel{\rightarrow}{F}[/tex], of magnitude 8.20 N and angle θ3 = 30.0° acts on P. All three vectors lie in the xy plane. About the origin, what are the magnitude of (a) the angular momentum of the particle and (b) the torque acting on the particle?
Homework Equations
[tex]\tau[/tex] = r x F
l = r x p = m (r x v)
The Attempt at a Solution
I found the x and y components of r and v.
I used those in the 2nd equation above to solve for l which is angular momentum.
Then I used the 1st equation to solve for torque.
I found the x and y components of F and solved for torque.
I don't know what I'm doing wrong here.
I used cross product as indicated. =/