Unit of Momentum

The Unit of momentum is kg.m/s. Momentum is a fundamental concept in physics that describes the quantity of motion possessed by an object. It is a vector quantity, meaning it has both magnitude and direction. It is product of mass of an object and velocity with which it is moving. It is measured in the unit of kg.m/s

In this article, we will learn in detail about unit of momentum, which includes its SI Unit and other units. We will also learn how to convert one unit of momentum into other using conversion factor.

Definition of Momentum

Momentum (p) is the product of an object’s mass (m) and its velocity (v). In mathematical terms, momentum is given by the formula:

p = mv

Where

• p = momentum
• m = mass
• v = velocity

What is Unit of Momentum?

The unit of momentum is kilogram meter per second (kg·m/s) in the International System of Units (SI).

1 kg·m/s of momentum means an object with a mass of 1 kilogram is moving at a velocity of 1 meter per second.

SI Unit of Momentum

The international system of Units (SI) officially adopts the kilogram meter per second (kg·m/s) as the SI Unit of the Momentum. Thus, the standardization sets the consistent framework for providing a comprehensive measure of an object’s motion.

Other units of Momentum

In addition to the standard SI unit of momentum, there are other units used in various contexts. Here are some alternative units of momentum along with their conversion factors:

Unit	Conversion Factor
Newton second (N·s)	1 kg·m/s = 1 N·s
Gram centimeter per second (g·cm/s)	1 kg·m/s = 1000 g·cm/s
Kilonewton second (kN·s)	1 kg·m/s = 0.001 kN·s

Conversions of Momentum Units

Converting between units is straightforward with the proper conversion factors. Here is the table containing conversion factor to convert momentum from one unit to other.

From	To	Conversion Factor
kg·m/s	N·s	1 kg·m/s = 1 N·s
kg·m/s	g·cm/s	1 kg·m/s = 1000 g·cm/s
kg·m/s	kN·s	1 kg·m/s = 0.001 kN·s

Conclusion

One of the most critical concepts of physics is momentum, in the unit kg·m/s. It is the measure of energy particles or objects have in terms of their mass and velocity. Familiarizing with its unit and conversions opens way to accurate measurements and evaluations on diverse scientific backgrounds.

Examples on Unit of Momentum

Example 1: Calculate the momentum of a 2-kilogram object moving at a velocity of 3 meters per second.

Solution :

In order to calculate the momentum , we use the following formula : p = mv

where, m = mass of the object

v = velocity of the object

p = mv = 2 × 3 = 6 kg·m/s.

p = 6 kg·m/s.

Example 2: Convert 500 gram centimeters per second (g·cm/s) of momentum to kilogram meter per second (kg·m/s).

Solution :

First, convert grams to kilograms by dividing by 1000 (since 1 kg = 1000 g):

500g = 500/1000kg = 0.5kg

Then, convert centimeters to meters by dividing by 100 (since I m = 100 cm):

500 cm/s = 500/100 m/s = 5 m/s

Now, calculate the momentum using the converted values and the formula :p=mv

p = 0.5 kg × 5 m/s = 2.5 kg.m/s

Example 3: Determine the velocity of an object with a momentum of 150 N·s and a mass of 30 kilograms.

Solution :

Given momentum p = 150 N.s and mass is 30 kg, rearrange the formula p = mv to solve for velocity v:

v = p / m;

v = 150 / 30;

v = 5 m/s

Therefore, the velocity of the object is 5 meters per second (m/s).

Example 4: A ball with a mass of 0.2 kilograms is thrown with a velocity of 15 meters per second. Calculate its momentum.

Solution:

Using the formula

p = mv

p = mv, where m = 0.2 kg and v = 15 m/s,

p = 0.2kg × 15m/s = 3kg.m/s

Example 5: Convert 800 newton seconds (N·s) of momentum to kilogram meters per second (kg·m/s).

Solution:

Since 1 N·s = 1 kg·m/s, the momentum remains the same, which is 800 kg·m/s.

Example 6 : A truck with a mass of 1500 kg is moving at a velocity of 25 m/s. What is its momentum?

Solution:

Using the formula

p = mv

p = mv, where m = 1500 kg and v = 25 m/s,

p = 1500kg × 25m/s = 37500kg.m/s = 1500 kg×25 m/s = 37500 kg.m/s.

Example 7: Convert 1000 gram meters per second (g·m/s) of momentum to kilogram meters per second (kg·m/s).

Solution:

Since 1 g = 0.001 kg, the momentum in kg·m/s is 1000g.m/s×0.001=1kg .m/s1000 g.m/s×0.001=1 kg.m/s.

Example 8: An object has a momentum of 24 N·s and a velocity of 6 m/s. Calculate its mass.

Solution:

Using the formula

p = mv

and rearranging to solve for mass (m):

m = p/v = 24N.s/6m/s = 4kg

Practice Questions on Unit of Momentum

Q1: A bicycle with a mass of 10 kg is moving at a velocity of 8 m/s. Calculate its momentum.

Q2: Convert 300 kilogram meters per second (kg·m/s) of momentum to newton seconds (N·s).

Q3: An object has a momentum of 40 kg·m/s and a velocity of 5 m/s. Determine its mass.

Q4: A rocket with a mass of 2000 kg is traveling with a momentum of 12000 kg·m/s. What is its velocity?

Q5: Calculate the momentum of a 0.5-kilogram object moving at a velocity of 20 meters per second.

Frequently Asked Questions on Unit of Momentum

What is the SI unit of momentum?

The basic unit of momentum in SI is kilogram meter per second (kg⋅m/s).

How do I calculate momentum?

Momentum (p) is evaluated using the formula p = mv, which is having m as mass and v as velocity.

Can momentum be transferred between objects?

Yes, momentum is exchanged between objects by collisions and other contact relations.

How does mass affect an object’s momentum?

The more the mass of the object, the more its momentum with a given velocity, as momentum is directly proportional to mass.

Is momentum a vector or scalar quantity?

Momentum is a vector quantity since it has two attributes: magnitude (mass times velocity) and direction (same direction as the velocity.

Can momentum be negative?

Yes, indeed, the momentum can be negative as it is a vector quantity, hence, according to direction it can be negative