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(Work, Energy & Power)

Conservation of mechanical energy

Conservation of Mechanical Energy

What is Conservation of Energy?

The principle of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. In a closed system, the total energy remains constant.

For example, when a ball is thrown into the air, its energy transforms between kinetic and potential energy, but the total mechanical energy remains the same.

Types of Mechanical Energy

  • Kinetic Energy (KE): The energy of motion. Calculated using the formula: KE=12mv2KE = \frac{1}{2}mv^2 where mm is mass and vv is velocity.
  • Potential Energy (PE): The energy stored due to an object's position or condition. For gravitational potential energy: PE=mghPE = mgh where mm is mass, gg is acceleration due to gravity, and hh is height.

Conservation of Mechanical Energy

In the absence of non-conservative forces (like friction), the total mechanical energy (sum of kinetic and potential energy) in a system remains constant:

Total Mechanical Energy=KE+PE=constant\text{Total Mechanical Energy} = KE + PE = \text{constant}

Worked Example

A roller coaster car of mass 500 kg is at the top of a hill 20 m high. Calculate its speed at the bottom of the hill.

Tuity Tip

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Remember: Energy transformations are key! Watch how energy shifts between kinetic and potential forms.

Real-World Application: This principle is crucial in designing roller coasters, ensuring safety and fun!

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