Displacement of a Pendulum to find Work done by Force

AI Thread Summary
The discussion revolves around calculating the work done by a force on a pendulum, with initial equations derived for tension and force in relation to angles. The participant expresses uncertainty about the direction of displacement and the relevance of using conservation of energy in this context. It is noted that the work done by the force could result in potential energy, kinetic energy, or frictional losses. For those opting for integration, the force's horizontal component is emphasized, requiring a transformation of variables from θ to dx. The conversation highlights the complexities of analyzing work done in a pendulum system.
shinify
Messages
4
Reaction score
0
rBUh8Gt.png

7w1eBsJ.png

GIANCOLI.ch07.p86.jpg


I'm having trouble with this problem. I did: FTcosθ-mg= 0, solving for FT, getting FT= mg/cosθ. Then, along the x-axis, F-FTsinθ=0, solving for F, getting F= mgtanθ. Not sure how to go about it from here. What is the direction of the displacement?
 
Physics news on Phys.org
The force is always horizontal, so for the work done you want the horizontal displacement. But.. why not just use conservation of energy?
 
What do you mean?
 
The force has done work on the system. Where has that work gone? There are three possibilities: PE, KE and frictional losses. Which apply here?
If you want to do it by integration, ∫F.ds, since the force acts horizontally that becomes ∫F.dx, where F is the scalar magnitude of F and dx is the horizontal component of ds. You have F as a function of θ, so next you need dx in terms of θ and dθ.
 

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

Work done on a conical pendulum
Replies
3
Views
2K
Work Done by Friction & Gravity on Incline: Explained
Replies
7
Views
7K
What is the smallest value of angular displacement of the raft?
2
Replies
54
Views
3K
Misunderstanding Work-energy theorem and center of mass properties
Replies
7
Views
2K
Is the line integral of tangential force in pendulum equal to the negative of change in potential energy?
Replies
3
Views
838
Intuitive explanation of why work done by tension is 0?
Replies
5
Views
2K
Spring constant formlula for Force and Work Done
Replies
12
Views
2K
Work energy theorem problem -- Block sliding up a curved incline
Replies
10
Views
1K
Seeking advice on "simple" pendulum problem
Replies
27
Views
2K
A block dropping onto a spring system
2
Replies
58
Views
2K

Hot Threads

Recent Insights

Back
Top