Sanity check please -- Load cable swinging outward on a rotating crane

AI Thread Summary
The discussion focuses on the physics of load cables swinging outward on a rotating crane, utilizing the equation Fcp = -m*w^2*r. Participants analyze the relationship between variables, particularly how to express r1 and r2 in terms of other parameters. There is a debate about the relevance of certain variables, with a suggestion that one variable may not be necessary. The importance of understanding the radius of rotation, R, as the sum of r1 and r2 is emphasized. The conversation concludes with a confirmation of the calculations and a light-hearted acknowledgment of simplifying the equation.
Thickmax
Messages
31
Reaction score
8
Homework Statement
Please can my work be sanity checked? I think I'm on the right lines
Relevant Equations
See below
1624914062559.png
So I know

Fcp=-m*w^2*r

So from the equation -m*w^2*r=m*g*tan(theta)

r = r1+r2

so to rewrite

-m*(w^2)*(r1+r2)=m*g*tan(theta)
So
r1+r2=(m*g*tan(theta))/-m*(w^2)

r1=((m*g*tan(theta))/-m*(w^2)) - r2

Am I doing this nearly correct?
 
Last edited by a moderator:
Physics news on Phys.org
Thickmax said:
Am I doing this nearly correct?
Yes, but one of your variables is not in the list of those allowed in the answer. Can you see a way to get rid of it?
 
Shouldn't ##r_2## be directly proportional to ##\omega^2##?
 
Lnewqban said:
Shouldn't ##r_2## be directly proportional to ##\omega^2##?
No the crane rotates around its base column, the radius of rotation is ##R=r_1+r_2## not just ##r_2##.
 
haruspex said:
Yes, but one of your variables is not in the list of those allowed in the answer. Can you see a way to get rid of it?
I can indeed! m's are overrated! Thank you for the confirmation
 
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 .
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Thread 'A bead-mass oscillatory system problem'
I can't figure out how to find the velocity of the particle at 37 degrees. Basically the bead moves with velocity towards right let's call it v1. The particle moves with some velocity v2. In frame of the bead, the particle is performing circular motion. So v of particle wrt bead would be perpendicular to the string. But how would I find the velocity of particle in ground frame? I tried using vectors to figure it out and the angle is coming out to be extremely long. One equation is by work...
Back
Top