# Maximum kinetic energy of a pendulum

• jforce93
In summary, the question asks for the maximum kinetic energy of a pendulum with a mass of 3.2 kg, a length of 1.5 meters, and a swing through an arc of 17 degrees. The potential energy can be calculated using the formula PE = mgh, but the height at 17 degrees should be 0.43856 meters. The correct answer to the question is 2.1 Joules.
jforce93

## Homework Statement

Okay, so I'm using the online Giancoli physics thing for AP Physics C summer work (see: "([PLAIN]http://wps.prenhall.com/esm_giancoli_physicsppa_6"[/URL]. I think my way of doing it is correct, but the online checker says I'm wrong.
The question: "A pendulum has a mass of 3.2 kg, a length of 1.5 meters, and swings through a (half)arc of 17 degrees. To the nearest tenth of a Joule, what is its maximum kinetic energy of the pendulum?"

PE = mgh
KE = 1/2mv^2

## The Attempt at a Solution

Find the PE of the pendulum. The height of it at 17 degrees: .43856 meters (about).
PE = 3.2*9.81*.43856 = 13.767 Joules. But the online checker says 2.1 Joules.

What am I doing wrong? Or, am I doing it right, the online thing is just wrong?

Thanks,

Jordan

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Your height for the pendulum bob is not correct.

## 1. What is the maximum kinetic energy of a pendulum?

The maximum kinetic energy of a pendulum is the highest amount of energy that the pendulum has while in motion. It occurs at the bottom of the swing, when the pendulum is moving at its fastest speed.

## 2. How is the maximum kinetic energy of a pendulum calculated?

The maximum kinetic energy of a pendulum can be calculated using the equation K = 1/2 * m * v^2, where K is the kinetic energy, m is the mass of the pendulum, and v is the velocity at the bottom of the swing.

## 3. Does the length of the pendulum affect its maximum kinetic energy?

Yes, the length of the pendulum does affect its maximum kinetic energy. A longer pendulum will have a higher maximum kinetic energy than a shorter pendulum, as it has a greater distance to travel and therefore a higher velocity at the bottom of the swing.

## 4. What factors can affect the maximum kinetic energy of a pendulum?

The maximum kinetic energy of a pendulum can be affected by several factors, such as the mass of the pendulum, the length of the pendulum, and the force acting on the pendulum (such as gravity or air resistance).

## 5. How does the maximum kinetic energy of a pendulum relate to its potential energy?

The maximum kinetic energy of a pendulum is directly related to its potential energy. As the pendulum swings from one side to the other, its potential energy is converted into kinetic energy. The maximum kinetic energy occurs when the potential energy is at its lowest point, and vice versa.

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