A point particle is located in the first quadrant of the x - y plane (at x = +x_

Question

A point particle is located in the first quadrant of the x - y plane (at x = +x_0 and y = +y_0) and is traveling in a straight line in the positive y-direction. The particle is not rotating. Does this point particle have angular momentum as measured from the origin? If so. what is its direction? No. The angular momentum is zero. Yes. The angular momentum is in the positive x-direction Yes. The angular momentum is in the negative x-direction Yes. The angular momentum is in the positive y-direction Yes. The angular momentum is in the negative y-direction Yes. The angular momentum is in the positive z-direction Yes. The angular momentum is in the negative z-direction Disk A is spinning without friction with constant angular speed. Disk B is then set atop disk A Due to friction between the two disks, disk A slows and disk B speeds up; eventually they reach a new common angular speed. The only friction anywhere is between the two disks. Is the total angular momentum of the two disks constant during this interaction? Why or why not? No. Angular momentum decrease due to friction between the two disks. No. Angular momentum increases due to friction. Yes. Angular momentum is constant because angular momentum is always conserved in any system for any situation. Yes. Angular momentum is constant because the friction torque is internal to the system. Look at the Stop-To-Think problem about the spinning rain buckets. Read it thoroughly so you know what's going on. Is angular momentum conserved in this case? No. Angular momentum is not conserved. Yes. Angular momentum is conserved.

Explanation / Answer

Given the point particle is in xy plane and moving in a straight line in the + y direction

that is along the +y axis and which is at perpendicular distance from the y axis is +x

here the angular momentum is L = r_perpendiculaat*momentum of the particle

here r perpendicular is along +x direction and the linear momentum is along +y direction then

the directionof the angular momentum is L = mv r sin theta which is in -ve Z direction

angular momentum is along -ve z direction

Question3

   the angular momentum will be conserved

let I1,I2 are the momenta of inertia of the system before and after placing disk B on A , due to friction the angular speed of disk A decreases and reaches a value and

the angular speed of the disk B increases from zero to a common value

so the by conservation of angular momentum
   L1 = L2

   I1W1 + 0 = (I2) W -----------(because W of B is zero)

here I1 is moment of inertia of disk A (IA)

   I2 = (IA+IB)
so the conservation of angular momentum takes place.

the option third is answer

Question 4

Angular momentu is conserved in the case of spinning rain buckets

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