Net kinetic energy refers to the total kinetic energy of a system. It's calculated by summing the kinetic energy of all individual components within the system.
Calculating Net Kinetic Energy
To find the net kinetic energy, you need to follow these steps:
- Identify the system: Define the system you're interested in. This could be a collection of particles, a moving object, or a group of objects interacting with each other.
- Determine the kinetic energy of each component: Calculate the kinetic energy of each individual component within the system using the formula:
- *KE = 1/2 mv²**
Where:- KE is the kinetic energy
- m is the mass
- v is the velocity
- *KE = 1/2 mv²**
- Sum the individual kinetic energies: Add up the kinetic energy of all components to obtain the net kinetic energy of the system.
Example
Consider a system of two objects:
- Object 1: mass = 2 kg, velocity = 5 m/s
- Object 2: mass = 3 kg, velocity = 2 m/s
Calculation:
- KE1 = 1/2 2 kg (5 m/s)² = 25 J
- KE2 = 1/2 3 kg (2 m/s)² = 6 J
Net Kinetic Energy: KE1 + KE2 = 25 J + 6 J = 31 J
Practical Insights
- Internal Energy: The net kinetic energy of a system is a part of its internal energy. Internal energy also includes potential energy and other forms of energy within the system.
- Frame of Reference: The net kinetic energy of a system depends on the chosen frame of reference. For example, a system at rest relative to one observer might have non-zero kinetic energy relative to another observer in motion.
