Mechanical energy

Definition

Mechanical energy is the sum of kinetic energy and potential energy in a system. It is the energy associated with the motion and position of an object.

5 Must Know Facts For Your Next Test

1. Mechanical energy is conserved in an isolated system with no non-conservative forces (e.g., friction) acting on it.
2. The total mechanical energy (TME) can be expressed as $TME = KE + PE$, where $KE$ stands for kinetic energy and $PE$ stands for potential energy.
3. Potential energy can be gravitational, elastic, or another form depending on the force involved.
4. Kinetic energy depends on the mass and velocity of an object, given by $KE = \frac{1}{2}mv^2$.
5. In scenarios involving conservative forces only, mechanical energy remains constant throughout the motion.

Review Questions

• What components make up mechanical energy?
• How does mechanical energy change in a system with no non-conservative forces?
• Explain how potential and kinetic energies contribute to total mechanical energy.

Related terms

Kinetic Energy:

The energy that an object possesses due to its motion, calculated as $KE = \frac{1}{2}mv^2$.

Potential Energy:

The stored energy of an object due to its position or state, such as gravitational potential energy ($PE = mgh$) or elastic potential energy.

Conservation of Energy:

A principle stating that the total energy in an isolated system remains constant over time.