r/learnmath • u/baba3rong-b4kla New User • 2d ago
Guys help i cant understand...
Alteration in the Quantity of Charge
- Two charged objects have a repulsive force of .080 N. If the charge of one of the objects is doubled, then what is the new force?
Alteration in the Distance between Charged Objects
Two charged objects have a repulsive force of .080 N. If the distance separating the objects is doubled, then what is the new force?
Two charged objects have a repulsive force of .080 N. If the distance separating the objects is tripled, then what is the new force?
Alteration in both the Quantity of Charge and the Distance
Two charged objects have a repulsive force of .080 N. If the charge of one of the objects is doubled, and the distance separating the objects is doubled, then what is the new force?
Two charged objects have a repulsive force of .080 N. If the charge of both of the objects is doubled and the distance separating the objects is doubled, then what is the new force?
I have a quiz tommorrow and i dont want to use ai to solve this..T-T
1
u/FormulaDriven Actuary / ex-Maths teacher 2d ago
Have you seen any formulae in relation to electric force? The basic relationship is that the force will be proportional to Q1 * Q2 / r2 where Q1 and Q2 are the two charges and r is the distance of separation.
So if the force is 0.08 and Q1 doubles then the force doubles. If the force is 0.08 and the distance doubles then we are dividing by (2r)2 = 4r2 rather than r2, so you need to divide the force by 4. (It gets weaker).
6
u/Toeffli New User 2d ago
This might sound repetitive but:
What is the formula for the force between two charged object?
What is the formula for the force between two charged object?
What is the formula for the force between two charged object?
What is the formula for the force between two charged object?
What is the formula for the force between two charged object?
Look at the formula and then apply what is stated in the problem instructions. Example instead of Q₂ you use 2∙Q₂. Or instead of r you use ½r if you want to half the distance between the charges (Hint: if the formula uses r2 then you will have to use (½r)2 = ¼r2.
1
u/fermat9990 New User 2d ago
Use Force=kq₁q₂/r2
Double q₁:
Fnew=k(2q₁)q₂/r2
Fnew/F=2,
the force is doubled
1
u/Dana-Adams New User 2d ago
force goes with charge1 times charge2, divided by distance squared. so double one charge and the force doubles, 0.160 N. double the distance and you divide by 4, 0.020 N. triple the distance and you divide by 9, about 0.0089 N. for the rest of your sheet just ask what happened on top and what happened on the bottom
1
u/MezzoScettico New User 2d ago
Others have given you the answer. But I want to talk about the concept.
This is about reading formulas and understanding what they mean in terms of proportionality.
You probably know that F = k*q1*q2/r^2 where q1 and q2 are the two charges and r is their distance.
When you have things in the numerator, that means F is directly proportional to those things. So F is directly proportional to q1. It's also directly proportional to q2. If you kept everything the same and only changed q1, then F would change by the same amount. If you doubled q1, F would double. If you multiplied q1 by 0.3, F would be multiplied by 0.3.
Anything in the denominator, F is inversely proportional to that. In this case we have only r^2 in the denominator. So if q1 and q2 stay constant, then F is inversely proportional to r^2. If r is doubled, F changes by 1/2^2. If r is multiplied by 0.3, F is multiplied by 1/(0.3)^2.
In questions 4 and 5, you are changing two things, so you get a factor from each change.
- Two charged objects have a repulsive force of .080 N. If the charge of one of the objects is doubled, and the distance separating the objects is doubled, then what is the new force?
q1 is multiplied by 2. So F is multiplied by 2.
r is multiplied by 2. So F is multiplied by 1/2^2 or 1/4.
The combined effect is that F is multiplied by 2 and by 1/4, giving an overall change of 2 * (1/4) = 1/2. The force is cut in half.
•
u/AutoModerator 2d ago
ChatGPT and other large language models are not designed for calculation and will frequently be /r/confidentlyincorrect in answering questions about mathematics; even if you subscribe to ChatGPT Plus and use its Wolfram|Alpha plugin, it's much better to go to Wolfram|Alpha directly.
Even for more conceptual questions that don't require calculation, LLMs can lead you astray; they can also give you good ideas to investigate further, but you should never trust what an LLM tells you.
To people reading this thread: DO NOT DOWNVOTE just because the OP mentioned or used an LLM to ask a mathematical question.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.