Relationships between potential energy and distance

AI Thread Summary
Gravitational potential energy increases with distance due to the formula mgh, indicating a direct relationship. In contrast, electric potential energy decreases with distance, as shown by the formula kq1q2/r, demonstrating an inverse relationship. The gravitational attraction can be expressed as Gm1m2/d², highlighting a similarity to electric forces. When considering small changes in distance relative to the overall distance, gravitational attraction appears nearly constant, justifying the use of mgh. Understanding these distinctions is crucial for grasping the differences in potential energy behaviors between gravitational and electric forces.
henry3369
Messages
194
Reaction score
0
Why is gravitational potential energy directly related to the distance of between two objects (mgh, so as distance increases, potential energy increases) while electric potential energy is inversely related (kq1q2/r,distance increases, electric potential energy decreases)?
 
Physics news on Phys.org
henry3369 said:
Why is gravitational potential energy directly related to the distance of between two objects (mgh, so as distance increases, potential energy increases) while electric potential energy is inversely related (kq1q2/r,distance increases, electric potential energy decreases)?
Well, it isn't. If you look at it macroscopically, the gravity attraction is \frac{Gm_{1}m_{2}}{d^{2}}. See the similarity?
Locally, when a change in distance is small compared to the basic distance, the gravity attraction is almost constant and you can do the mgh thing.
 

Thread '1:1 versus 2:1 Mechanical Advantage debate'

The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
View full post »

Thread 'Newton's first law?'

Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
View full post »
Thread 'Beam on an inclined plane'

Thread 'Beam on an inclined plane'

Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
View full post »

Similar threads

B Can energy be decomposed?
Replies
2
Views
1K
Gravitational potential energy -- Why is it always negative?
Replies
10
Views
3K
Question about potential energy: gravity and a vertical spring
Replies
12
Views
4K
Gravitational potential energy question -- Ojbect sitting on the Earth
Replies
3
Views
1K
B Difference Between Potential and Potential Energy
2
Replies
55
Views
4K
I How to interpret this definition of potential energy?
Replies
10
Views
2K
B Work and energy: conceptual doubt
Replies
2
Views
2K
Is there any motion hidden within potential energy?
Replies
7
Views
1K
Vertical spring, the relationship between potential energies
Replies
10
Views
2K
Conservative forces, Nonconservative forces and Potential Energy
Replies
9
Views
3K

Hot Threads

Recent Insights

Back
Top