Momentum Calculator
Calculate linear momentum using p = mv with mass and velocity inputs. Free online physics tool for collision, impulse, and mechanics problems with instant results.
About This Calculator
The Momentum Calculator computes the linear momentum of an object using the physics formula p = m × v, where p is momentum, m is mass, and v is velocity. This fundamental equation from Newtonian mechanics helps students, engineers, and physics enthusiasts analyze moving objects in collision problems, impulse calculations, and conservation of momentum scenarios. Whether you are studying for a physics exam, designing safety systems, or analyzing sports dynamics, momentum calculations are essential for understanding how objects interact during motion.
Momentum is a vector quantity with the same direction as the velocity. The SI unit of momentum is the kilogram-meter per second (kg·m/s), also equivalent to the newton-second (N·s). This calculator also converts the input velocity from meters per second (m/s) to kilometers per hour (km/h) for practical everyday reference. For example, a 70 kg person walking at 1.4 m/s (5 km/h) has a momentum of 98 kg·m/s, while a 1000 kg car moving at 20 m/s (72 km/h) carries 20,000 kg·m/s of momentum.
Understanding momentum is essential for analyzing collisions (elastic and inelastic), calculating impulse (force × time), and applying the conservation of momentum principle in closed systems. In elastic collisions, both momentum and kinetic energy are conserved, while in inelastic collisions only momentum is conserved. This principle is used in everything from car crash safety design to rocket propulsion, where the conservation of momentum explains how rockets accelerate by expelling exhaust gases backward.
This calculator provides a detailed breakdown showing how mass and velocity individually contribute to the total momentum, helping users understand the relationship between these two variables. The interactive bar and pie charts visualize the momentum distribution, making it easier to grasp the concept for students and educators alike.
Regional Notes
Worldwide: This calculator uses SI units (kg, m/s, kg·m/s) which are the international standard for scientific and engineering calculations worldwide. The velocity conversion to km/h is provided for everyday reference across all regions. In the United States, miles per hour (mph) is commonly used for vehicle speeds, while most other countries use km/h.
Frequently Asked Questions
What is momentum in physics?
Momentum is the product of an object's mass and velocity, calculated using the formula p = mv. It is a vector quantity with SI units of kg·m/s, representing the quantity of motion an object possesses.
How do you calculate momentum?
Momentum is calculated by multiplying the mass of an object by its velocity: p = m × v. For example, a 10 kg object moving at 5 m/s has a momentum of 50 kg·m/s.
What is the difference between momentum and velocity?
Velocity is the rate of change of position (speed with direction), while momentum is mass times velocity. Two objects can have the same velocity but different momentum if they have different masses.
How is momentum related to force?
According to Newton's second law, force equals the rate of change of momentum: F = dp/dt. A larger force or longer duration of force application results in a greater change in momentum.
What is the law of conservation of momentum?
The law of conservation of momentum states that the total momentum of an isolated system remains constant when no external forces act on it. This principle is fundamental in collision analysis, rocket propulsion, and many physics problems.
What units are used for momentum?
The SI unit of momentum is kilogram-meter per second (kg·m/s), which is equivalent to newton-second (N·s). In imperial units, momentum is measured in pound-foot per second (lb·ft/s).
Can momentum be negative?
Yes, momentum is a vector quantity so it can be negative depending on the direction of motion. In one-dimensional calculations, a negative velocity produces negative momentum, indicating motion in the opposite direction.