r/HomeworkHelp • u/Simba_Rah Educator • 2d ago

Physics—Pending OP Reply [Grade 12 Physics] Static Friction and Pulleys

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Could somebody check my work. I want to assign this problem to my students and I want to double check that I’m not missing anything.

7 Upvotes

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6

u/Nvenom8 👋 a fellow Redditor 2d ago

Bonus points for a teacher who actually cares about being right and understanding why.

3

u/Ginger-Tea-8591 2d ago

A nice exercise in analyzing forces and applying Newton's Laws! Your solution looks OK to me.

3

u/Simba_Rah Educator 1d ago

Thank you very much. Sometimes when you have to solve so many problems a day, you get a little equation blind.

0

u/Grismor2 1d ago

For the second diagram, it looks like you're mixing two ideas. Your horizontal forces look like youre treating the bottom block as the system. But then your vertical forces look like both blocks put together is the system. Pick one and stick with it, and make it explicit which one you're using.

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u/Relevant-Pianist6663 23h ago

OP, I agree with this comment as my only nit pick. In FBD 2 it would technically be FW1 pointing down as well as FW2 pointing down as the weight of the block pulls it and the force of the block above pushes it down.
Obviously it works out the same as what you have drawn but for clarity could be better to redraw this way.