How to calculate change in kinetic energy

Kinetic energy is the energy possessed by an object due to its motion. It is an essential attribute to understand in various scientific fields, including physics, engineering, and even everyday life. In this article, we will explore how to calculate the change in kinetic energy of an object and provide a step-by-step guide for doing it.
Step 1: Understand the Basic Concept of Kinetic Energy
Before diving into the calculation process, it is important to grasp the concept of kinetic energy. The kinetic energy of an object can be described as the work required to accelerate that object from rest to its current velocity. Once the object gains velocity, it thereby possesses kinetic energy. The amount of this energy depends on both the object’s mass and velocity.
Step 2: Learn the Formula for Kinetic Energy
The formula used for calculating kinetic energy (KE) is as follows:
KE = 1/2 * m * v^2
In this formula, KE represents kinetic energy, m denotes the object’s mass (in kilograms), and v stands for its velocity (in meters per second).
Step 3: Calculate Initial and Final Kinetic Energies
To find the change in kinetic energy, you need to determine both the initial and final kinetic energies of an object. This involves using the formula provided above twice—once for each state (initial and final).
For instance, let’s assume you have an object with a mass of 5 kg. Its initial velocity is 3 m/s, and its final velocity is 7 m/s.
To calculate the initial kinetic energy:
Initial KE = 1/2 * m * (initial v)^2
= 1/2 * 5 * (3)^2
= 22.5 J
To calculate the final kinetic energy:
Final KE = 1/2 * m * (final v)^2
= 1/2 * 5 * (7)^2
= 122.5 J
Step 4: Calculate Change in Kinetic Energy
Now that you have the initial and final kinetic energies, you can determine the change in kinetic energy by subtracting the initial value from the final value.
Change in KE = Final KE – Initial KE
= 122.5 J – 22.5 J
= 100 J
In this example, the change in kinetic energy is 100 Joules. A positive value signifies that the object has gained kinetic energy, while a negative value indicates a loss of kinetic energy.
Conclusion
Calculating the change in kinetic energy is a useful skill in understanding various principles within the realm of science, such as work-energy theorem or conservation of energy. With this step-by-step guide at your disposal, you are now well-equipped to calculate the change in kinetic energy for any given object with ease.