Show that the force applied by each rope

Click For Summary
SUMMARY

The discussion centers on calculating the force applied by two ropes supporting a 400N load at a 40-degree angle to the horizontal. Each rope exerts a tension of approximately 312.5N, which is rounded to about 300N for simplicity. The upward force from each rope is derived using the equation Fy = F * sin(angle), leading to the conclusion that the combined upward force from both ropes nearly equals the weight of the load, confirming the system's equilibrium.

PREREQUISITES
  • Understanding of basic physics concepts, particularly forces and equilibrium.
  • Familiarity with trigonometric functions, especially sine and cosine.
  • Ability to solve simultaneous equations involving forces.
  • Knowledge of vector components in two-dimensional systems.
NEXT STEPS
  • Study the principles of static equilibrium in physics.
  • Learn how to apply trigonometric functions in force resolution.
  • Explore the concept of tension in ropes and cables under load.
  • Investigate the use of free-body diagrams for analyzing forces in systems.
USEFUL FOR

Students studying physics, engineers working with load-bearing systems, and anyone interested in understanding the mechanics of tension and forces in static equilibrium.

Gughanath
Messages
118
Reaction score
0
please help!

i don't know how to solve da problem please help:

Two ropes are used to carry a load of weight 400N. The ropes are 40 degrees to the horizontal. Show that the force applied by each rope is to the container is abou 300N.
 
Physics news on Phys.org
in order to hold up an object weighing 400 Newtons, you must apply a force of 400 Newtons upward to counter act the force of weight.

if you have two ropes, at 40 degree angles, holding it up, then you know that the combined upward force those ropes are exerting on the object must be 400 Newtons.

also, if you kow the "resultant" force in each rope, the force along the hypotenuse of the imaginary triangle, and the angle of each, then you can calculate what the ropes' upward forces are,
Fy = F * sin(angle), where Fy is the upward force, F is the total resultant force.
so it is 300 * sin(40) = 193 Newtons upward, and there are 2 ropes exerting the same force, so the total upward force is 386 Newtons. this isn't quite the 400 Newtons that we were looking for, but is close enough I think sonsidering they only used 1 sig. fig in the question, then 1 sig fig in the answer would be 400 Newtons.
 
Gughanath said:
i don't know how to solve da problem please help:

Two ropes are used to carry a load of weight 400N. The ropes are 40 degrees to the horizontal. Show that the force applied by each rope is to the container is abou 300N.


By symmetry of the problem (I'm assuming it is because you didn't say it wasn't), the tension in each rope provides 200N of force in the upward direction. This upward force can also be written in terms of the tension T in the rope:

\mbox{upward force} = T \sin 40^{\circ} = 200N

Now you can solve for T, which is what you are looking for.
 
Here's my guess:

<br /> -T_1\cos(40)+T_2\cos(40)=0<br /> <br /> T_1\sin(40)+T_2\sin(40)-400N=0<br />

Those two are equations above are for your x- and y-coordinates. The force must equal zero.

The first equation simplifies into:

<br /> T_1=T_2\cos(40)/\cos(40)<br />

*T just stands for tension of cables 1 and 2

Now plug in T_1 into the second equation.

<br /> T_2\cos(40)\sin(40)/cos(40) + T_2\sin(40)=400 N<br /> <br /> = T_2\left(\cos(40)sin(40)/cos(40)\right)+sin(40)=400 N<br /> <br /> = T_2\left(1.28\right)=400 N<br /> <br /> = T_2=312.5 N<br />

Now you know tension of one cable, then just plug it in your original equation:

<br /> T_1=T_2\cos(40)/cos(40)<br /> <br /> = T_1=312.5 N<br />

They equal about 300 N, like the problem says.

*I'm new with the latex equation stuff, so I'm sorry if these equations have mistakes.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
938
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
3
Views
1K
Replies
4
Views
863
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 25 ·
Replies
25
Views
2K
  • · Replies 19 ·
Replies
19
Views
1K