D What is the Missing Step in this Electrostatic Algebra Equation?

AI Thread Summary
The discussion centers on a homework question regarding electrostatic seesaws and algebraic manipulation. The individual is confused about how a specific term cancels out in the equation. It is clarified that there is no missing step; rather, two fractions with a common denominator can be combined. The example provided illustrates that adding fractions with the same denominator is straightforward. Understanding this concept resolves the confusion regarding the algebraic process.
spiderlegs
Messages
5
Reaction score
0

Homework Statement



I have a homework question on electrostatic seesaws. My problem is the algebra.

Homework Equations



I have been following another example and any guidance to help me proceed would be great.

0= (2q Q)/(4πε_o r²)+(q Q)/(4πε_o r²)-m
0= (3q Q)/(4πε_o r²)-m
m=(3q Q)/(4πε_o r²)

I don't understand line 2. I don't understand how part of the equation has canceled out. I know there is a step missing so could anyone point me in the right direction.

The Attempt at a Solution

 
Physics news on Phys.org
There is no step missing.

There are two fractions which are the same, therefore they can be added:
\frac{2x}{y} + \frac{x}{y} = \frac{3x}{y}
 
Of course! Thank you compuchip x
 
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...

Similar threads

Back
Top