- #1
victorc
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These are two word problems, so I don't think the template applies to this thread.
1. Two strong magnets are on opposite sides of a tabletop's surface so that the attraction between the magnets is all that is holding up the one underneath. Identify all forces which involve either magnet (either as the agent or the object being acted upon), and all associated action/ reaction pairs completely. Number each pair.
My attempt at this question:
The forces on the magnet above the table include the magnetic pull by the other magnet (pointing down) [as well as the force of gravity (pointing down) and the normal force exerted by the table (upwards)]. The forces on the magnet below the table include the force caused by the magnetic field (upwards) [as well as the force of gravity (downwards)]. The magnetic field created by the two magnets generates a long-range magnetic force on each of the magnets causing the attraction between them.
There are no action/reaction pairs because there is no acceleration involved with either of the objects.
2. Two blocks, A and B, are hanging from opposite ends of a massless string which runs over a massless frictionless pulley. The mass of block A is greater than that of block B. Rank, from largest to smallest, all of the forces acting on either block. (Don't bother to include in this ranking the forces acting on the string.) Put your answer in the usual form: X > Y = Z. Explain why you ranked each force in order.
My attempt at this question:
Forces acting on block B (from largest to smallest):
1. Upwards force caused by tension of the string.
2. Downwards force of gravity (weight).
Forces acting on block A (from largest to smallest):
1. Downwards force of gravity (weight).
2. Upwards force caused by tension of the string.
ps:. I don't understand what the question means with "Put your answer in the usual form: X > Y = Z."
Thanks in advance
1. Two strong magnets are on opposite sides of a tabletop's surface so that the attraction between the magnets is all that is holding up the one underneath. Identify all forces which involve either magnet (either as the agent or the object being acted upon), and all associated action/ reaction pairs completely. Number each pair.
My attempt at this question:
The forces on the magnet above the table include the magnetic pull by the other magnet (pointing down) [as well as the force of gravity (pointing down) and the normal force exerted by the table (upwards)]. The forces on the magnet below the table include the force caused by the magnetic field (upwards) [as well as the force of gravity (downwards)]. The magnetic field created by the two magnets generates a long-range magnetic force on each of the magnets causing the attraction between them.
There are no action/reaction pairs because there is no acceleration involved with either of the objects.
2. Two blocks, A and B, are hanging from opposite ends of a massless string which runs over a massless frictionless pulley. The mass of block A is greater than that of block B. Rank, from largest to smallest, all of the forces acting on either block. (Don't bother to include in this ranking the forces acting on the string.) Put your answer in the usual form: X > Y = Z. Explain why you ranked each force in order.
My attempt at this question:
Forces acting on block B (from largest to smallest):
1. Upwards force caused by tension of the string.
2. Downwards force of gravity (weight).
Forces acting on block A (from largest to smallest):
1. Downwards force of gravity (weight).
2. Upwards force caused by tension of the string.
ps:. I don't understand what the question means with "Put your answer in the usual form: X > Y = Z."
Thanks in advance