- #1
JimmyRay
- 89
- 0
Kinetic energy and gravitational potential energy are inversely proportionate to each other?
Are Kinetic Energy and Gravitational Potential Energy Inversely Proportionate?
- Thread starter JimmyRay
- Start date
AI Thread Summary
Kinetic energy and gravitational potential energy are not inversely proportional, despite their relationship in a closed system where total energy remains constant. The equation E_t = U_g + K illustrates that as one form of energy increases, the other decreases, but this does not equate to an inverse proportionality. The analogy of transferring quarters highlights the concept of energy transfer rather than a strict mathematical relationship. The discussion emphasizes the importance of understanding energy conservation rather than misinterpreting the nature of their relationship. Overall, the relationship between kinetic and gravitational potential energy is one of balance, not inverse proportion.
- #2
dav2008
Gold Member
- 588
- 1
No.
If A is inversly proportional to B that means that A \propto \frac{1}{B}
In the case of kinetic energy K and gravitational potential energy U_g it can be said that the total energy in a system is E_t = U_g + K
Obviously there are numerous other forms of energy but the above case can be applied when you're dealing with gravity only.
If A is inversly proportional to B that means that A \propto \frac{1}{B}
In the case of kinetic energy K and gravitational potential energy U_g it can be said that the total energy in a system is E_t = U_g + K
Obviously there are numerous other forms of energy but the above case can be applied when you're dealing with gravity only.
- #3
- 7,253
- 2,740
No.
For an object in freefall, K+U=(a constant, E)... that is, K=E-U.
This, however, does not mean K=c/U, where c is a proportionality constant.
For an object in freefall, K+U=(a constant, E)... that is, K=E-U.
This, however, does not mean K=c/U, where c is a proportionality constant.
- #4
JimmyRay
- 89
- 0
Ohh... hmm is that the only way they are related?
K + U = Et
Because I just saw that, as Kinetic energy increases gravitational potential decreases and vice versa, THAT statement is correct right? Thats why I thought inversely proportional...
thanks guys
K + U = Et
Because I just saw that, as Kinetic energy increases gravitational potential decreases and vice versa, THAT statement is correct right? Thats why I thought inversely proportional...
thanks guys
- #5
Math Is Hard
Staff Emeritus
Science Advisor
Gold Member
- 4,650
- 39
I always think of it like accounting. Let's say I have a dollar in quarters. I give you a quarter, so now I have 75 cents, and you have 25 cents. I give you another quarter, so now we both have 50 cents. If I give you my last two quarters, you have a dollar, and I've got nothing. So you're amount increases as mine decreases, and the reverse would be true if you started handing quarters back to me, but this isn't the same as an inversely proportional relationship. It's just debit and credit from one side to the other.
Take my example with a grain of salt though - this is just my way of thinking about it. My wacky physics teacher used to say, "sometimes Mr. Potential Energy got it all and sometimes Mr. Kinetic Energy got it all!"
Take my example with a grain of salt though - this is just my way of thinking about it. My wacky physics teacher used to say, "sometimes Mr. Potential Energy got it all and sometimes Mr. Kinetic Energy got it all!"
Last edited:
- #6
JimmyRay
- 89
- 0
Thats a good way to look at it.
Neglect gravity other than that of water; neglect friction.
F1=ρgsh=1000*10*1*(1+4)=50000 N;
F1=ρgsh=1000*10*0.1*4=4000 N;
F3=50000-4000=46000 N?
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system
$$M(t) = M_{C} + m(t)$$
$$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$
$$P_i = Mv + u \, dm$$
$$P_f = (M + dm)(v + dv)$$
$$\Delta P = M \, dv + (v - u) \, dm$$
$$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$
$$F = u \frac{dm}{dt} = \rho A u^2$$
from conservation of momentum , the cannon recoils with the same force which it applies.
$$\quad \frac{dm}{dt}...
I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are;
Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction.
Must be LESS than 1 kg.
NO parachutes.
NO glue or Tape can touch the egg.
MUST be able to take egg out in less than 1 minute.
Grade A large eggs will be used.
Similar threads
Hot Threads
-
Torque biomechanics
- Started by Naucus
- Replies: 6
- Introductory Physics Homework Help
-
Work Done in slowly pulling a thread
- Started by Bling Fizikst
- Replies: 28
- Introductory Physics Homework Help
Recent Insights
-
Insights Why Entangled Photon-Polarization Qubits Violate Bell’s Inequality
- Started by Greg Bernhardt
- Replies: 7
- Quantum Physics
-
Insights Quantum Entanglement is a Kinematic Fact, not a Dynamical Effect
- Started by Greg Bernhardt
- Replies: 11
- Quantum Physics
-
Insights What Exactly is Dirac’s Delta Function? - Insight
- Started by Greg Bernhardt
- Replies: 5
- General Math
-
Insights Relativator (Circular Slide-Rule): Simulated with Desmos - Insight
- Started by Greg Bernhardt
- Replies: 1
- Special and General Relativity
-
Insights Fixing Things Which Can Go Wrong With Complex Numbers
- Started by PAllen
- Replies: 10
- General Math
-
Insights Fermat's Last Theorem
- Started by fresh_42
- Replies: 105
- General Math