• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer

CBSE Tuts

CBSE Maths notes, CBSE physics notes, CBSE chemistry notes

  • NCERT Solutions
    • NCERT Solutions for Class 12 English Flamingo and Vistas
    • NCERT Solutions for Class 11 English
    • NCERT Solutions for Class 11 Hindi
    • NCERT Solutions for Class 12 Hindi
    • NCERT Books Free Download
  • TS Grewal
    • TS Grewal Class 12 Accountancy Solutions
    • TS Grewal Class 11 Accountancy Solutions
  • CBSE Sample Papers
  • NCERT Exemplar Problems
  • English Grammar
    • Wordfeud Cheat
  • MCQ Questions

Momentum Definition, Formula and Explaination

Physics Topics can be both theoretical and experimental, with scientists using a range of tools and techniques to understand the phenomena they investigate.

Introduction to Momentum with Examples

In order to understand Newton’s second law of motion, we should first know the meaning of the term ‘momentum’ of a moving body (or moving object). This is discussed below.
We know that a cricket ball is much more heavy than a tennis ball. Suppose we throw a cricket ball and a tennis ball, both with the same speed or velocity. It will be found that more force is required to stop the cricket ball (which has more mass) and less force is required to stop the tennis ball (which has less mass).
Momentum Definition and Meaning 1
We conclude that the force required to stop a moving body is directly proportional to its mass. Now, if we throw two cricket balls of the same mass at different speeds or velocities, it will be found that more force is required to stop that cricket ball which is moving with higher velocity and less force is required to stop the cricket ball moving with lower velocity. So, we conclude that the force required to stop a moving body is also directly proportional to its velocity. Thus, the quantity of motion in a body depends on the mass and velocity of the body. This gives us another term known as “momentum”. The momentum of a body is defined as the product of its mass and velocity.
Thus, Momentum = mass × velocity
or, p = m × v
where p = momentum
m = mass of the body
and v = velocity (or speed) of the body

It is clear that if a body is at rest, its velocity is zero and hence its momentum is also zero. Thus, the total momentum of the gun and bullet before firing is zero because their velocity is zero. Momentum is a vector quantity and takes place in the direction of velocity. We have just seen that, momentum = mass × velocity. Now, mass is measured in kilograms (kg) and velocity is measured in metres per second (m/s), so the SI unit of momentum is kilogram metres per second which is written as kg.m/s or kg.m s-1.

Every moving body possesses momentum. Since momentum depends on the mass and velocity of a body, so a body will have a large momentum :
(a) if its mass is large, or
(b) if its velocity (speed) is large, or
(c) if both its mass and velocity (speed) are large. We will now discuss some everyday situations which involve large momentum. A karate player can break a pile of tiles or a slab of ice with a single blow of his hand. This is because a karate player strikes the pile of tiles or the slab of ice with his hand very, very
Momentum Definition and Meaning 2
fast. In doing so, the large momentum of the fast moving hand is reduced to zero in a very, very short time. This exerts a very large force on the pile of tiles or the ice slab which is sufficient to break them apart.

Though a cricket ball is not very heavy but when it is thrown with a high speed (or high velocity), it acquires a very large momentum and sometimes hurts the batsman. This is why a batsman often ducks to a bouncer. On the other hand, a car or bus may not be running at a high speed (or high velocity) but because of its high mass, it has a very high momentum which may hurt the person coming in its way. It is a common observation that road accidents at high speeds are very much worse than accidents at low speeds.

This is because the momentum of vehicles running at high speeds is very high and causes a lot of damage to the vehicles and injuries to passengers during the collision. Thus, we are afraid of a moving cricket ball or a running vehicle because of the combined effect of their mass and velocity which is called momentum. From this discussion we conclude that the combined effect of mass and velocity of a body is taken into account by a physical quantity called momentum. In fact, momentum is considered to be a measure of the quantity of motion of a moving body. We can feel what momentum is if we happen to collide with a person running at top speed ! We will now solve a problem based on momentum.

Example Problem.
What is the momentum of a man of mass 75 kg when he walks with a uniform velocity of 2 m/s ?
Solution.
We know that:
Momentum = mass × velocity
= m × v
Here, Mass, m= 75 kg
And, Velocity, v = 2 m/s
Putting these values in the above formula, we get:
Momentum = 75 × 2 kg.m/s
= 150 kg.m/s

Primary Sidebar

NCERT Exemplar problems With Solutions CBSE Previous Year Questions with Solutoins CBSE Sample Papers
  • The Summer Of The Beautiful White Horse Answers
  • Job Application Letter class 12 Samples
  • Science Lab Manual Class 9
  • Letter to The Editor Class 12 Samples
  • Unseen Passage For Class 6 Answers
  • NCERT Solutions for Class 12 Hindi Core
  • Invitation and Replies Class 12 Examples
  • Advertisement Writing Class 11 Examples
  • Lab Manual Class 10 Science

Recent Posts

  • Understanding Diversity Question Answer Class 6 Social Science Civics Chapter 1 NCERT Solutions
  • Our Changing Earth Question Answer Class 7 Social Science Geography Chapter 3 NCERT Solutions
  • Inside Our Earth Question Answer Class 7 Social Science Geography Chapter 2 NCERT Solutions
  • Rulers and Buildings Question Answer Class 7 Social Science History Chapter 5 NCERT Solutions
  • On Equality Question Answer Class 7 Social Science Civics Chapter 1 NCERT Solutions
  • Role of the Government in Health Question Answer Class 7 Social Science Civics Chapter 2 NCERT Solutions
  • Vital Villages, Thriving Towns Question Answer Class 6 Social Science History Chapter 9 NCERT Solutions
  • New Empires and Kingdoms Question Answer Class 6 Social Science History Chapter 11 NCERT Solutions
  • The Delhi Sultans Question Answer Class 7 Social Science History Chapter 3 NCERT Solutions
  • The Mughal Empire Question Answer Class 7 Social Science History Chapter 4 NCERT Solutions
  • India: Climate Vegetation and Wildlife Question Answer Class 6 Social Science Geography Chapter 8 NCERT Solutions
  • Traders, Kings and Pilgrims Question Answer Class 6 Social Science History Chapter 10 NCERT Solutions
  • Environment Question Answer Class 7 Social Science Geography Chapter 1 NCERT Solutions
  • Understanding Advertising Question Answer Class 7 Social Science Civics Chapter 7 NCERT Solutions
  • The Making of Regional Cultures Question Answer Class 7 Social Science History Chapter 9 NCERT Solutions

Footer

Maths NCERT Solutions

NCERT Solutions for Class 12 Maths
NCERT Solutions for Class 11 Maths
NCERT Solutions for Class 10 Maths
NCERT Solutions for Class 9 Maths
NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 7 Maths
NCERT Solutions for Class 6 Maths

SCIENCE NCERT SOLUTIONS

NCERT Solutions for Class 12 Physics
NCERT Solutions for Class 12 Chemistry
NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry
NCERT Solutions for Class 10 Science
NCERT Solutions for Class 9 Science
NCERT Solutions for Class 7 Science
MCQ Questions NCERT Solutions
CBSE Sample Papers
NCERT Exemplar Solutions LCM and GCF Calculator
TS Grewal Accountancy Class 12 Solutions
TS Grewal Accountancy Class 11 Solutions