What is the tension in the rope problem?

  • Thread starter Thread starter pttest
  • Start date Start date
  • Tags Tags
    Rope Tension
AI Thread Summary
The discussion centers on calculating the tension in a rope with two buckets of different weights hanging from it. Initially, when the lighter bucket is held, the tension equals the weight of the heavier bucket at 130 N. Upon releasing the lighter bucket, the tension should account for the net force, but the initial calculation of 65 N is incorrect. Once both buckets come to rest, the tension equals the weight of the lighter bucket at 65 N. Participants are encouraged to apply Newton's 2nd Law and analyze the acceleration of each bucket to accurately determine the tension throughout the scenarios.
pttest
Messages
16
Reaction score
0

Homework Statement


Buckets and a Pulley Two buckets of sand hang from opposite ends of a rope that passes over an ideal pulley. One bucket is full and weighs 130 N; the other bucket is only partly filled and weighs 65 N.
a) Initially, you hold onto the lighter bucket to keep it from moving. What is the tension in the rope?
b) You release the lighter bucket and the heavier one descends. What is the tension in the rope now?
c) Eventually the heavier bucket lands and the two buckets come to rest. What is the tension in the rope now?


Homework Equations





The Attempt at a Solution


a) Initially, you hold onto the lighter bucket to keep it from moving. What is the tension in the rope?
Tension is equal of the weight of the first bucket
T= 130N

b) You release the lighter bucket and the heavier one descends. What is the tension in the rope now?
Tension is equal of the weight difference between the of the first and secong buckets.
T= 130 - 65= 65N (But this answer is wrong. Could someone please explain?)

c) Eventually the heavier bucket lands and the two buckets come to rest. What is the tension in the rope now?
Tension is equal of the weight of the second bucket
T= 65N
 
Physics news on Phys.org


for b) have you drawn a free body diagram of the buckets in flight?
 


Yes, I did draw a free body diagram. In second situation since the heavier one descends (due to force of gravity) and the lighter one moves upwards I subtracted 65N from 130N.

Am I in right track? If not could you please explain...?

Thanks in advance
 


Unfortunately this question isn't that simple. Having drawn your free body diagrams, use Newton's 2nd Law on each bucket. What can you say about the acceleration of each bucket? Can you then solve for the tension?
 
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...
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...
Back
Top