Statics Problem: Weight Hanging from a Rope

In summary, the conversation discusses a problem involving a mass hanging from a pulley and a mass on a rope. The solution involves adding the moments at the pulley and equating them to 0, resulting in the equation 2*50sin(x)=1. The solution also involves drawing a free body diagram and finding the change in length of the rope over the horizontal section, which is equal to the change in height of the vertical section. The solution ultimately arrives at the answer H=L/100.
  • #1
wwshr87
59
0

Homework Statement


Mass hanging from the pulley in 50kg, the mass on the rope is 1kg. Please see attachment for details. The answer will be in terms on L.


Homework Equations


The sum of the forces in the y-direction and x-direction are equal to 0.


The Attempt at a Solution


Adding the moments at the pulley and equating them to 0; we have that T=50.
Now a free body diagram of the second weight. 2*50sin(x)=1, sinx=(1/100)=H/X
X=(L^2+H^2)^(1/2), substituding this in (1/100)=H/X, and solving for H, I find H=L/100.
Which is not the answer I have in the solutions.
Any help will be greatly appreciated.
 

Attachments

  • prob1.png
    prob1.png
    4.2 KB · Views: 500
  • staticproblem1.png
    staticproblem1.png
    8.1 KB · Views: 472
Physics news on Phys.org
  • #2
Can you explain to me "2*50sin(x)=1"?
 
  • #3
When I draw the FBD of the 1kg weight; I addthe forces in the y-direction
50*sin(x)+50*sin(x)=1
 
  • #4
What is the answer that they give?
 
  • #5
I have attached the solution. I cannot follow what they are doing; if anybody does please help.
 

Attachments

  • solutionprob5.png
    solutionprob5.png
    14.5 KB · Views: 493
  • #6
The key here is that they are asking how much the 50kg weight will move up due to the 1kg weight. the Solution shows the change in length of the rope over the horizontal section, which is the same as the change in height of the vertical section, which is the same as the 50kg mass.
 
  • #7
Ok, I understand that now. But I still don't get where the 50/L is coming from.
 
  • #8
sin(tetha)=50/L
 
  • #9
Ok got it, thanks for the explanation.
 

Related to Statics Problem: Weight Hanging from a Rope

1. How do I calculate the weight of an object hanging from a rope?

The weight of an object hanging from a rope can be calculated using the formula W = m x g, where W is the weight in Newtons, m is the mass in kilograms, and g is the acceleration due to gravity (9.8 m/s^2). Simply multiply the mass of the object by 9.8 to determine its weight.

2. What is the tension in the rope if a weight is hanging from it?

The tension in the rope is equal to the weight of the object. This is because the rope is being pulled in two opposite directions - one by the weight of the object and the other by the force of gravity acting on the object. The tension in the rope must be equal to these two forces in order to keep the object suspended.

3. Does the length of the rope affect the weight of the object?

Yes, the length of the rope can affect the weight of the object. The longer the rope, the more it will stretch and the more it will sag under the weight of the object. This means that the weight of the object will be slightly reduced due to the rope's elasticity. However, for most practical purposes, the effect of the rope's length on the weight of the object is negligible.

4. How does the angle of the rope affect the weight of the object?

The angle of the rope affects the weight of the object by changing the direction of the force acting on the rope. As the angle increases, the horizontal component of the force acting on the rope also increases. This means that the tension in the rope will decrease, resulting in a decrease in the weight of the object. The weight of the object will be at its maximum when the rope is at a 90 degree angle with the ground.

5. Can I use the weight of an object hanging from a rope to determine the strength of the rope?

No, the weight of an object hanging from a rope does not provide enough information to determine the strength of the rope. Other factors such as the material, diameter, and construction of the rope also play a role in its strength. To determine the strength of a rope, it is necessary to conduct specific strength tests according to industry standards.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
204
  • Introductory Physics Homework Help
Replies
7
Views
359
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
22
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Introductory Physics Homework Help
Replies
19
Views
839
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
518
Back
Top