Plank + Beam Physics style questions

Dear Physics teacher, I really appreciate this wonderful site.

I understand how to use the Torque formula. My issue is getting the Plank and Beam calculations questions and formulating an algebraic equation to solve. I always draw a diagram
Can you kindly elaborate on a strategy to solve this style of question
I have tried the ESA questions L2 Physics P 124 Q10,11,12 .

How is this question usually asked too i.e in what style


Hi @sphysics ,

Sorry for my slow reply. Here are a couple of video guides (1, 2, 3, 4) that lay out the steps I would reccommend you follow. These should also give you some ideas around how the questions might be asked. Here is a similar post with response that may give you some insight.

If you still aren’t sure after that, let me know a question you have in mind, perhaps one of your ESA ones, and I’ll create a solution for you.

You could then pratice some with the collated exam questions from No Brain Too Small. Make sure you check your work with their answers.

I hope that helps. Let me know how you get on.

hi i had question regarding the youtube link above about the AME Torque Bridge Problem p-127. isnt the distance betweeen Cynthia and the force support A 1.50m, however in the video it’s mentioned as 1.00m. i am also not being able to understand how you got 3.5m from support A to where stan is cause i got 3m from subtracting 1m (the distance between stan and support B) from 4m (the distance from support A to support B). inorder to find how far stan is from support A. would you please be able to show how you got 3.5m.

Hi @anne

Great question. The full length of the beam is 5 metres. We then identify a pivot, in this video I pick support A as our pivot. We should also note that eah support is 0.5m from the ends of the beam. Since Cynthia is 1.5m from the end of the beam, she is therefore 1.0m from our pivot.

Stan is 1.0m from the right hand end of the beam. Since the pivot is 0.5m from the left hand end there must be 3.5m from our pivot to Stan. (5.0 - 1.0 - 0.5 = 3.5m)

Does that help? Some of the values in the question are hard to see due to my hands, but I think you can read them in the opening few seconds of the video.

For a bit of practice, you could try this question with support B as your pivot. The final answers should be exactly the same.

oh okay, know i understand. Thank you.

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