# Tagged Questions

The law of conservation of energy, which states that the amount of energy in a system is constant. For questions about Earth's environment, see the climate-science tag instead.

461 views

### Max extension of spring mass system

While attempting problems of simple harmonic motion I came across this problem, which has gotten me confused. A fixed horizontal spring is stretched by a constant force $F$. I am required to obtain ...
52 views

### Applying conservation of energy to a railgun problem?

When a projectile is lunched due to the Lorentz force($F_L$), how can I apply the conservation of energy that the electrical energy inputted to generate the Lorentz force & magnetic field equals ...
53 views

97 views

### How does the tension force of a massless string affect the speed of a mass on its end?

i,j, and k are the unit vectors in the following question, and $\omega$ is the angular velocity. Lets say you have a mass m attached to a mass-less string of length $L$ tied to a peg with no friction....
130 views

40 views

### Non-linear pendulum (Whittaker's treatise on analytical dynamics of particles)

Reading through Whittaker's "treatise on the analytical dynamics of particles and rigid bodies" I have a question regarding his analysis of the simple nonlinear pendulum at chapter IV. At some point ...
23 views

### energy conservation in an electric circuit

Define a reactive (lossless) and reciprocal two-port by its impedance matrix $[Z]$, so that $[Z]+[\bar Z] = [0]$ and let the source impedance and open circuit source voltage be $Z_s$ and $V_s$ at ...
2k views

### Where does the energy go in a rocket when no work is done?

While playing Kerbal Space Program, I wondered where my chemical energy would go when fired at 90° to the motion. It would do no work on the rocket, but all that energy has to go somewhere, right? ...
44 views

### Simple harmonic motion, maximum kinetic energy [closed]

Why kinetic energy is maximum at mean position?
40 views

### Heat, Work and Internal energy in closed systems

This has been troubling me for a while now. I know that the performed work equals $P\Delta V$ for isobaric systems and I know that in isochoric systems no work is done, but how do I find the heat $Q$? ...
84 views

### Work done by gravitational force!

Suppose a ball is $10m$ high from the ground. It will have $E_p = 10mg$. Now, if the ball falls freely then we know $E_k$ will be $0.5mv^2 = E_p$. But it is said that the work done by a force will ...
124 views

### Using Gravity for Infinite energy?

Can gravity be used as an infinite energy source? What if you throw objects down, say a hill, and had a panel on the bottom that would use the force of the fall and convert it to energy? Would this ...
53 views

### Why can we find forces like this using energy methods?

Often to calculate forces in complex situations (usually involving complicated mathematics), I have seen various people employ energy methods. The answer comes out correct, but I can't understand why ...
18 views

### Solving a first order non linear differential equation in the specific case of the orbit of a particle moving under a central conservative force

Hello it's my first time posting in here and I hope someone in here can help me as my teachers quite dislike questions that aren't specifically in the curriculum. I'm reading About classical mechanics ...
74 views

### How to evaluate energy conservation for magnetization?

A permanent magnet can attract a certain magnetic material mass, giving a certain amount of energy $U_{mag}$. If we first use this magnet to magnetize $n$ ferromagnetic pieces, we would have $n$ ...
52 views

### Potential Energy in a System and its Relation to the Total Energy

In this answer it was stated that potential energy is a property of a system and not an individual particle. If we have two particles (1 and 2) interacting via a conservative force, we can write an ...
106 views

### Bernoulli equation as an energy conservation equation

I don’t want to learn and apply Bernoulli's equation. It is complicated and you need to remember a lot. I instead want to apply energy conservation. But I don't always find it easy. For example, when ...
88 views

### Is throwing a ball upwards an isolated or non-isolated system?

We have to write a lab report on an experiment where a ball is thrown upwards and it's motion is detected by a motion sensor, i am just confused whether the system is isolated or non-isolated
53 views

216 views

### Energy loss in Capacitors

We have this formula in our textbook for loss of energy when two capacitors are connected together. They mention that it is due to heat dissipation. However, we have not considered any such term in ...
53 views

### Does $v^2=v_0^2-2gh$ work if the positive axis is up and the initial velocity is down?

In the situation where the positive axis is up, the acceleration due to gravity is $g$, and the velocity is represented by the equation $v^2=v_0^2 - 2gh$. This works great if the initial velocity is ...
### In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again?
In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again? As everything in tries to attain lowest energy possible ...