Solve Rotational Motion Homework: Pulleys A, B, C

AI Thread Summary
The discussion revolves around solving a homework problem related to rotational motion involving pulleys A, B, and C. The user initially struggles with the lack of acceleration information and the differences in angular and linear velocities for compound and contact pulleys. They attempt to use the formula s = rδ to find the angular displacement but realize they need information about pulleys B and C for the complete solution. After receiving guidance from another user, the original poster successfully solves the problem. The thread highlights the importance of understanding the relationships between linear and angular motion in pulley systems.
freshbox
Messages
290
Reaction score
0

Homework Statement


Attached 1st pic is the question, 2nd pic is the formula

PS: I am sorry if i have posted on the wrong section.

The Attempt at a Solution


My understanding for this question is for compound pulley, angular velocity is the same, linear velocity is different. For pulleys in contact, linear velocity is the same and angular velocity is different.

Since in this case, A/B are compound pulleys whereas B/C are contact pulleys.
But the question did not give me any acceleration info on any of the pulleys, so I don't know where to start..

The only info that I can gather is:

ωi=0m/s²
s=17m
t=20s

So I tried to use s=rδ formula.
17=0.15δ
δ=113.33

Although I managed to get "1" of the answer, but the info I used was all from pulley A but the answer they want is gears B/C so I'm abit confused here.
Hope someone can help me out.Thanks.
 

Attachments

  • q1.jpg
    q1.jpg
    39.2 KB · Views: 468
  • formula.jpg
    formula.jpg
    11.8 KB · Views: 375
Physics news on Phys.org
welcome to pf!

hi freshbox! welcome to pf! :smile:
freshbox said:
… the question did not give me any acceleration info on any of the pulleys, so I don't know where to start..

start by finding the (linear) acceleration of the weight D :wink:
 
Hi tiny-tim thanks for the tip, i solved the problem already :)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Mass and pulley system (Rotational Dynamics)
Replies
9
Views
2K
Solving for Velocity on a Pulley System
Replies
3
Views
1K
Simple Harmonic Motion with Rotational Inertia
Replies
6
Views
4K
How does unbalanced tension affect the motion of a rope?
Replies
9
Views
3K
How Do You Calculate the Angular Motion of a Pulley System?
Replies
15
Views
2K
Falling Mass on a Pulley - Rotational Energy
Replies
9
Views
2K
Blocks falling while attatched to pulley
Replies
6
Views
2K
System of two wheels of different sizes with an axle through their centers
2
Replies
67
Views
4K
Two pulleys and two masses on a slope
Replies
2
Views
2K
Avg Power in a Rotational Energy/Work Problem
Replies
6
Views
1K

Hot Threads

Recent Insights

Back
Top