Calculating Kinetic Energy for a Swinging Wrecking Ball

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In summary, a 315kg wrecking ball is suspended by a crane on a 10.0m cable. The angle between the cable and the vertical is 30.0º. The potential energy of the ball at its lowest position can be easily calculated, while the kinetic energy and speed of the ball when it falls back to the vertical position can be found using the equation KE = ½ mv². As there is no loss of energy in the system, the potential energy will be converted entirely into kinetic energy. Therefore, KE = PE.
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Zeitgeist
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A wrecking ball, with mass of 315kg, hangs from a crane on 10.0m of cable. If the crane swings the wrecking ball so that the angle that the cable makes with the vertical is 30.0º, what is the potential energy of the ball in relation to its lowest positio? What will be the kinetic energy of the wrecking ball when it falls back to the vertical position? What will be the speed of the wrecking ball?

I have no problem finiding the potential energy, but I don't know how to calculate the kinetic energy. and i know EK = ½ mv², but i don't know how to use it here. What should I do?
 
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  • #2
In the system as you describe it, there is no loss of energy, so any potential energy is going to be converted completely into kinetic energy.
In other words, KE = PE!
 
  • #3
Thanx alot
 

1. What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is a form of energy that an object has as a result of its velocity and mass.

2. How is kinetic energy calculated?

Kinetic energy is calculated by multiplying the mass of an object by the square of its velocity, and then dividing by two. The formula for kinetic energy is KE = 1/2 * m * v^2.

3. What are some examples of kinetic energy?

Some examples of kinetic energy include a moving car, a swinging pendulum, a rolling ball, and a jumping athlete. Essentially, any object that is in motion has kinetic energy.

4. How does kinetic energy relate to potential energy?

Kinetic energy and potential energy are two forms of energy that can be converted into one another. Kinetic energy is the energy an object has due to its motion, while potential energy is the energy an object has due to its position or state. For example, a roller coaster at the top of a hill has potential energy, but as it goes down the hill, that potential energy is converted into kinetic energy.

5. How is kinetic energy important in daily life?

Kinetic energy plays a crucial role in our daily lives. It is a fundamental concept in physics and is used in various applications, such as transportation, sports, and electricity generation. Understanding kinetic energy allows us to design and improve technologies that make our lives easier and more efficient.

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