A block is connected to a weight through a massless rope, which goes over a pull
ID: 1527582 • Letter: A
Question
A block is connected to a weight through a massless rope, which goes over a pulley. The block is given an initial push, so that it slides along the table to the right. There is friction between the block and the table. The mass of the hanging weight is larger than the mass of the block. The figure below shows the block while it is still moving to the right and the free body diagrams for the weight and the block.
Some students discuss the free-body diagrams.
Alice: “I see a problem in the diagram for the weight. The two forces should
have the same magnitude.”
Bob: “But the weight is moving upward – there should be a greater force
in that direction.”
Carlo: “No, that diagram is ok, but there is a problem with the diagram for
the block. The frictional force is in the wrong direction.”
David: “Both diagrams are correct, because they show the way both objects
Would be accelerating.”
Who do you agree with? Explain your reasoning.
Alice ___ Bob ___ Carlo ___ David ___ None of them ___
While i agree with carlo, what about alice should the two objects have the same magnitude?
v 2 m/s block on table rope on weight +F table on block rope on block T Y F Earth on block F Earth on weightExplanation / Answer
the force equation for it should read
Frope - Fweight = ma
But since the whole setup moves with constant velocity
So a = 0
Hence both magnitudes should be equal
Also
friction force should be acting on the block in backward direction
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.