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

  • #1
dcmf
9
4
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
  • #2
You have a sign error going from eqn 2 to eqn 3 (##F_{TA}=##).
 
  • Like
Likes erobz
  • #3
haruspex said:
You have a sign error going from eqn 2 to eqn 3 (##F_{TA}=##).
Haha I see it! Thank you so much 🤡
 

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
587
  • Introductory Physics Homework Help
Replies
10
Views
4K
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
755
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
8
Views
8K
  • Mechanical Engineering
Replies
18
Views
892
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
23
Views
4K
Back
Top