Find tension using sum of torque (two strings, one beam, one box)

Click For Summary
The discussion revolves around a physics problem involving torque, tension, and a beam with two strings and a box. The user is struggling with their final submission, having received incorrect messages despite following hints and using significant figures. They initially submitted a value of 49363.63, which was marked incorrect, and then tried 49400 with the same result. A key issue identified is a sign error in the calculations between equations, specifically from equation 2 to equation 3. The user expresses gratitude upon realizing the mistake.
dcmf
Messages
16
Reaction score
5
Homework Statement
The figure (Figure 1) shows a model of a crane that may be mounted on a truck. A rigid uniform horizontal bar of mass m1 = 90.0 kg and length L = 5.10 m is supported by two vertical massless strings. String A is attached at a distance d = 1.90 m from the left end of the bar and is connected to the top plate. String B is attached to the left end of the bar and is connected to the floor. An object of mass m2 = 2000 kg is supported by the crane at a distance x = 4.90 m from the left end of the bar. Throughout this problem, positive torque is counterclockwise and use 9.80 m/s2 for the magnitude of the acceleration due to gravity.

Find TA, the tension in string A.
Relevant Equations
Tnet=ΣFlsinθ, F=mg
Here's the picture of the situation described, provided by the question.
1710544579144.png


Here's a screenshot of the work I have done.
1710544594573.png


Here's a screenshot of the submission screen.
1710544453555.png


The issue is that I have one attempt left and am not sure what I am doing wrong. Based on the hints, I feel like I'm calculating it right and using the right significant figures but it's just not accepting my answer (which is strange because usually it doesn't care about significant figures). I submitted 49363.63 and was shown the incorrect message above telling me to round to 3 significant figure so I submitted 49400 and got the same message. I feel like there's got to be something really obvious I'm missing or a concept that I am not applying. I'd really appreciate the help! Thanks in advance
 
Physics news on Phys.org
You have a sign error going from eqn 2 to eqn 3 (##F_{TA}=##).
 
haruspex said:
You have a sign error going from eqn 2 to eqn 3 (##F_{TA}=##).
Haha I see it! Thank you so much 🤡
 
If have close pipe system with water inside pressurized at P1= 200 000Pa absolute, density 1000kg/m3, wider pipe diameter=2cm, contraction pipe diameter=1.49cm, that is contraction area ratio A1/A2=1.8 a) If water is stationary(pump OFF) and if I drill a hole anywhere at pipe, water will leak out, because pressure(200kPa) inside is higher than atmospheric pressure (101 325Pa). b)If I turn on pump and water start flowing with with v1=10m/s in A1 wider section, from Bernoulli equation I...

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 22 ·
Replies
22
Views
754
  • · Replies 14 ·
Replies
14
Views
1K
  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K