⚡ Kinetic Energy Calculator
Calculate kinetic energy
How to Use This Calculator
Enter Object Mass
Input the mass of the object in kilograms (kg). This is the amount of matter in the object. For example, a person might be 70 kg, a car 1500 kg, or a baseball 0.145 kg.
Enter Velocity
Enter the velocity of the object in meters per second (m/s). This is the speed and direction of the object's motion. For example, walking speed is about 1.4 m/s, running 5 m/s, and a car at highway speed is about 30 m/s.
Calculate Kinetic Energy
Click the "Calculate Kinetic Energy" button to compute the kinetic energy. The calculator uses the formula KE = ½mv² to determine the energy of motion.
Review Results
Review the calculated kinetic energy in Joules. The calculator also shows the step-by-step formula calculation so you can see how the result was obtained.
About Kinetic Energy Calculator
The Kinetic Energy Calculator computes the energy of motion for any moving object using the fundamental formula KE = ½mv². Kinetic energy is the energy an object possesses due to its motion and is one of the most important concepts in physics, used in mechanics, thermodynamics, and many other fields.
When to Use This Calculator
- Physics Homework: Solve kinetic energy problems quickly and accurately
- Engineering Calculations: Determine energy requirements for moving systems
- Sports Analysis: Calculate the energy of athletes, balls, or equipment in motion
- Vehicle Analysis: Understand the energy of moving vehicles for safety and design
- Educational Purposes: Learn about kinetic energy and its relationship to mass and velocity
Why Use Our Calculator?
- ✅ Step-by-Step Formula: Shows the calculation process
- ✅ Accurate Calculations: Uses the standard physics formula
- ✅ Instant Results: Get answers immediately
- ✅ Easy to Use: Simple interface with clear inputs
- ✅ Free to Use: No registration or payment required
Understanding Kinetic Energy
Kinetic energy is the energy an object has because of its motion. It depends on both the object's mass and its velocity, but velocity has a squared relationship—doubling the velocity quadruples the kinetic energy. This is why speed is so important in collisions: a car traveling at 60 km/h has four times the kinetic energy of a car at 30 km/h. Kinetic energy is measured in Joules (J) in the metric system, where 1 Joule = 1 kg·m²/s².
Formula
KE = ½mv²
Where:
- KE = Kinetic Energy (Joules)
- m = Mass (kilograms)
- v = Velocity (meters per second)
Example Calculation:
For an object with mass = 10 kg and velocity = 5 m/s:
KE = ½ × 10 × 5²
KE = 0.5 × 10 × 25
KE = 125 J
Important Note: The velocity is squared in the formula, which means kinetic energy increases with the square of velocity. This is why doubling the speed quadruples the energy!
Frequently Asked Questions
What is kinetic energy?
Kinetic energy is the energy an object possesses due to its motion. It's calculated as KE = ½mv², where m is mass and v is velocity. Any object in motion has kinetic energy, and this energy represents the work that would be required to bring the object to rest, or the work the object could do if it were stopped.
Why is velocity squared in the kinetic energy formula?
Velocity is squared because kinetic energy is derived from the work-energy theorem. Work (W = Fd) equals force times distance, and since force equals mass times acceleration (F = ma), and acceleration relates to velocity squared, the energy ends up proportional to v². This means doubling the velocity quadruples the kinetic energy, which is why speed is so critical in collisions.
Can kinetic energy be negative?
No, kinetic energy cannot be negative. Since the formula is KE = ½mv², and both mass and velocity squared are always positive (or zero), kinetic energy is always positive or zero. An object at rest has zero kinetic energy. If you get a negative result, check your calculations—velocity should be squared, not negative.
What units are used for kinetic energy?
Kinetic energy is measured in Joules (J) in the metric system, where 1 J = 1 kg·m²/s². In the imperial system, it's measured in foot-pounds (ft·lb). For very large energies, kilojoules (kJ) or megajoules (MJ) are used. For example, a car at highway speed might have 500,000 J = 500 kJ of kinetic energy.
How does kinetic energy relate to potential energy?
Kinetic energy and potential energy are both forms of mechanical energy. In many systems, they can be converted into each other. For example, a falling object converts gravitational potential energy into kinetic energy. In a closed system with no external forces, the total mechanical energy (KE + PE) is conserved—as one increases, the other decreases by the same amount.