A Uniform Beam Supported by a Cable

AI Thread Summary
A uniform 250 kg beam is supported by a cable, and the problem requires finding the tension in the cable without using torque. The discussion highlights confusion regarding the angles used for resolving the tension, noting that the cable's angle should be 60 degrees to the horizontal rather than the stated 20 degrees. Additionally, the absence of a frictional force at the ground is pointed out as a critical oversight in the calculations. The participants emphasize the importance of correctly identifying forces and angles in static equilibrium problems. Accurate resolution of forces is essential for determining the correct tension in the cable.
ginza88
Messages
1
Reaction score
0

Homework Statement



A uniform 250 kg beam is supported by a cable connected to the ceiling, as shown in the figure. The lower end of the beam rests on a rough, horizontal floor. What is the magnitude of the tension in this cable?

Image of the problem:
http://session.masteringphysics.com/problemAsset/1026378/6/yg.10.70.jpg

Homework Equations



Fnet=ma=0

The Attempt at a Solution



I know that this problem is easiest to complete using torques, but I was told to try it without using torque (if possible). That being said, here is my attempt:

http://imgur.com/jKr3tDC

I know that I got the right answer but I am not sure how. Aren't the 40 degrees and the 20 degrees are the wrong angles to use when using a horizontal/vertically oriented plane?
 
Physics news on Phys.org
Your working does indeed look wrong.
You show the tension resolving into T cos(20o) horizontally and T sin(20o) vertically, whereas the cable makes an angle 60o to the horizontal.
You don't show any frictional force at the ground, but there must be one.
 

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

Tension and net torque in a cable
Replies
10
Views
5K
Weight held by a beam and cable
Replies
2
Views
1K
What is the tension in the right cable?
Replies
4
Views
2K
Solve Static Equilibrium: Beam, 520N Force, Cable Tension
Replies
2
Views
2K
Torque and rotational equilibrium question
Replies
6
Views
4K
Cable car with 2 cable arrangement
Replies
1
Views
7K
Pin and cable supported by a beam
Replies
1
Views
2K
Equilibrium problem - Vertical beam, cable
Replies
9
Views
5K
Torque and Rotational Equilibrium with a slanted Rod/Cable
Replies
7
Views
3K
How Do You Calculate Tension in a Cable and Force on a Hinge?
Replies
2
Views
4K

Hot Threads

Recent Insights

Back
Top