Miike012
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What is the difference between
1. ΔU= Q*ΔV
2.U = 1/2*Q*ΔV
When do I use 1. and 2. ?
1. ΔU= Q*ΔV
2.U = 1/2*Q*ΔV
When do I use 1. and 2. ?
Miike012 said:What is the difference between
1. ΔU= Q*ΔV
2.U = 1/2*Q*ΔV
When do I use 1. and 2. ?
Miike012 said:U: Electric poten. energy.
V: Voltage, or electric potential
Q: Charge...
But the two equations are similar but one has a factor of .5...
Miike012 said:for instance what if I was asked .. what is the energy supplied by a battery in charging the capacitors... What eq. would I use?
Miike012 said:The equations are correct...
Here they are printed from the text.
Miike012 said:The equations are correct...
Here they are printed from the text.
I don't see any lowercase "v" anywhere in this discussionPeterO said:So why did one of the equations include q while the other included Q.
v and V are different - the first usually means velocity while the second has to do with "voltage"
I agree, that is exactly what that formula is telling us. If (usually point) charge moves through a potential difference ΔV, the formula tells us the change in potential energy.PeterO said:The first formula looks like it might be the amount the energy of a charge q gains/loses when subjected to a change in V
Yes, that is most certainly the energy stored in a capacitor that has a charge Q on one of it's plates, and a potential difference ΔV across the two plates.The second looks like the Energy stored when a capacitor is charged. After the first bit, that you quoted they continue to sub for the value of a capacitor (C) , or at least I assume that is dealing with Capacitors.
Redbelly98 said:I don't see any lowercase "v" anywhere in this discussion
I was pointing out that a lower case v in a formula is quite different to a capital V in another formula. I was bemused that you though that two formulae, one with a lower case q in it, and another with a capital Q in it referred to the same thing.
Particularly surprised that you thought they were interchangeable.
When I asked the question "Perhaps you have written one [or both] of the equations incorrectly?
You replied with "The equations are correct... Here they are printed from the text."
However, the equations from the text were different to your original post ? - they weren't correct!
I agree, that is exactly what that formula is telling us. If (usually point) charge moves through a potential difference ΔV, the formula tells us the change in potential energy.
Yes, that is most certainly the energy stored in a capacitor that has a charge Q on one of it's plates, and a potential difference ΔV across the two plates.
Redbelly98 said:Yes, that is most certainly the energy stored in a capacitor that has a charge Q on one of it's plates, and a potential difference ΔV across the two plates.