Angles Formed by Particles' Positional Vectors

AI Thread Summary
The discussion centers on determining the angle formed by the positional vectors of two particles, A and B, which move in opposite directions with different radii and angular velocities. Particle A has a radius R and angular velocity of 2w, while particle B has a radius of 2R and angular velocity of w. The angle between the vectors changes based on the time interval t = n/(2w), and the radius does not affect the angle. Participants note that the angle can be expressed in terms of n, leading to different values depending on n's definition, with 3pi/2 being one possible outcome if n = 1. The complexity arises from the lack of specific information about n, making the problem challenging to solve definitively.
davidpac
Messages
4
Reaction score
0
a particle A has a circular movement with radius R and angular velocity of 2w, a particle B has a radius of 2R and an angular velocity of w, both velocities remain constant. particle B rotates clockwise and particle A rotates anticlockwise for an interval of t = n/(2w)

what angle is formed by the positional vectors of these two particles?

the options are: 0, 3pi/2, pi/2, pi.

note: the vector of these two particle's movement have the same origin, their movement make two circles, which have the same origin. particle B's circle has double the radius of particle A.

They don't say absolutely anything about the value of n.

from a sketch I've made, I say the angle is pi/2. but again, it all depends on the value of n.

any ideas?
 
Physics news on Phys.org
Some information is missing since the angle between the positional vectors will always be changing. It seems that the radius of each circle doesn't matter in terms of the angle between the position vectors.

EDIT: You're right, the answer is in terms of n, but none of the options have n in them.
w * t for particle A = -n radians
w * t for particle B = n/2 radians.
 
I have written absolutely everything that they gave me, I'm also finding it impossible to solve this problem.
 
Why would your teacher give you R?
 
if for example n = 1, the angle would be 3pi/2. do you agree?
 
I guess it depends on how you define negative and positive, but yes I agree.
It would be 3pi/2 if you measured clockwise from A to B.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top