- #1
dhphysics
- 6
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I have 3 questions. I think the answers are correct, but I'm having trouble providing explanations.
Three particles have identical masses. Each particle experiences only the gravitational forces due to the other two particles. How should the particles be arranged so each one experiences a net gravitational force that has the same magnitude?
. The attempt at a solution
- I think you would put them at the corners of a equilateral triangle, because then they would be equidistant from each other, so their net gravitational forces are the same. Is this correct logic?
A 10-kg suitcase is placed on a scale that is in an elevator. Is the elevator accelerating up or down when the scale reads the following?
... 75 N?
. The attempt at a solution
The elevator is going down. I'm not sure how to come up with a correct reason; it is intuitive.
...120 N?
. The attempt at a solution
The elevator is going up. Again, how would I justify this in physics terms?
A person has a choice of either pushing or pulling a sled at a constant velocity. Friction is present. Does it require less force to push or to pull?
[FONT=verdana, helvetica, sans-serif]. The attempt at a solution
Pulling requires less force because if you pull, then you apply an upwards force and so friction is reduced, making the horizontal component of the force not needing to be as big.[/FONT]
Homework Statement
Three particles have identical masses. Each particle experiences only the gravitational forces due to the other two particles. How should the particles be arranged so each one experiences a net gravitational force that has the same magnitude?
. The attempt at a solution
- I think you would put them at the corners of a equilateral triangle, because then they would be equidistant from each other, so their net gravitational forces are the same. Is this correct logic?
Homework Statement
A 10-kg suitcase is placed on a scale that is in an elevator. Is the elevator accelerating up or down when the scale reads the following?
... 75 N?
. The attempt at a solution
The elevator is going down. I'm not sure how to come up with a correct reason; it is intuitive.
...120 N?
. The attempt at a solution
The elevator is going up. Again, how would I justify this in physics terms?
Homework Statement
A person has a choice of either pushing or pulling a sled at a constant velocity. Friction is present. Does it require less force to push or to pull?
[FONT=verdana, helvetica, sans-serif]. The attempt at a solution
Pulling requires less force because if you pull, then you apply an upwards force and so friction is reduced, making the horizontal component of the force not needing to be as big.[/FONT]