Total energy when potential graph is given

• nhmllr
In summary, the conversation discusses a problem involving a position vs time graph and determining the total energy of a particle. The motion appears to be simple harmonic motion, but the mass and zero point of potential energy are needed to calculate the energy. However, without this information, the problem seems incomplete and incorrect.
nhmllr
Total energy when positions vs time graph is given

Homework Equations

energy initial = energy final

The Attempt at a Solution

At the crest of each wave, the particle has only potential energy, and at the middle of each wave the particle has only kinetic energy, and these values are equal. By looking at the slope when the graph crosses the horizontal axis, you can determine that it travels at 5m/s then. After this point, I do not know how to continue.

Last edited:
Disregard.

You said the potential graph is given. Where is it?

ehild

ehild said:
You said the potential graph is given. Where is it?

ehild

I'm sorry, I mis-titled the post originally. The potential graph is not given, only the position vs time graph is given

The motion looks SHM. But you need the mass of the particle.

ehild

ehild said:
The motion looks SHM. But you need the mass of the particle.

ehild

I gave the entire problem. No mass was given, and nothing analogous to the spring constant was given. However, I think you can find the ratio of the two, as the period = 2π * sqrt(m/k) = 8. I don't see how that helps, though

You also know the amplitude, A=5 m. The energy of the SHM is 1/2 kA2. You need the mass.

You also need the zero point of potential energy. If it is SHM, the potential energy is zero at zero position, and it is never negative. Something is very wrong with the problem.

ehild

1. What is the significance of a potential graph in determining total energy?

A potential graph shows the potential energy of a system at different positions. The total energy of a system is the sum of its kinetic and potential energy. Therefore, the potential graph provides valuable information about the total energy of a system.

2. How is the total energy calculated from a potential graph?

The total energy can be calculated by finding the maximum and minimum points on the potential graph and then using the equation E = K + U, where E is the total energy, K is the kinetic energy, and U is the potential energy.

3. Can the total energy be negative on a potential graph?

Yes, the total energy can be negative on a potential graph. This indicates that the system has a net negative energy, which could be due to the presence of an attractive force.

4. How does the shape of a potential graph affect the total energy?

The shape of a potential graph can affect the total energy by changing the values of the maximum and minimum points. A steeper potential graph with higher peaks will result in a higher total energy, while a flatter potential graph with lower peaks will result in a lower total energy.

5. Can the total energy change over time on a potential graph?

No, the total energy remains constant over time on a potential graph. This is because the sum of the kinetic and potential energy remains constant in a closed system, according to the law of conservation of energy.

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