In physics, an inelastic collision occurs when some amount of kinetic energy of a colliding object/system is lost. The colliding particles stick together, and the maximum amount of kinetic energy is lost in a perfectly inelastic collision. In such cases, kinetic energy lost is used in bonding the two bodies together. Problems involving collisions are usually solved using the conservation of momentum and energy.
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Inelastic Collision Definition
An inelastic collision is such a type of collision that takes place between two objects in which some energy is lost. In the case of inelastic collision, momentum is conserved but the kinetic energy is not conserved. Most of the collisions in daily life are inelastic in nature.
- Inelastic collision
- Elastic collision
Perfectly Inelastic Collision
The special case of inelastic collision is known as a perfectly inelastic collision. Here, two objects stick together after collision and move as a single object. Refer to the figure above. For example, when a wet mudball is thrown against a wall, the mudball sticks to the wall.
Inelastic Collision Formula
When two objects collide under inelastic conditions, the final velocity with which the object moves is given by-
Where,
- V= Final velocity
- M1= mass of the first object in kgs
- M2= mas of the second object in kgs
- V1= initial velocity of the first object in m/s
- V2= initial velocity of the second object in m/s
Inelastic Collision in Two Dimension
For inelastic collision in two dimensions, conservation of momentum is applied separately along each axis. Since Momentum is a vector equation, there is one conservation of momentum equation per dimension. There is only one conservation of energy equation.
Inelastic Collision Examples
Most of the collision we see in our day to day life falls under inelastic collision. Some of them are listed below.
Real World Examples Of Inelastic Collision
- The ball is dropped from a certain height and it is unable to rise to its original height.
- When a soft mudball is thrown against the wall, it will stick to the wall.
- The accident of two vehicles
- A car hitting a tree
Inelastic Collision Kinetic Energy
In the case of inelastic collision, the kinetic energy is not conserved. The loss of kinetic energy is due to internal friction. It may turn into vibrational energy of the atoms, causing a heating effect and the bodies are deformed.
Elastic Collision
Any collision in which the collided objects get separated after the collision is known as an elastic collision. In the case of elastic collision, kinetic energy gets conserved. One must use both conservations of momentum and conservation of energy to find the motions of the objects later.
Some examples of elastic collisions are ping-pong balls, billiards, etc.
Watch the video and learn more about collision
Inelastic Collision Problems
Problem 1:
Shankha is going by a slippery snowy hill. He has a mass of 20kg, and he is sliding the hill at a velocity of 5m/s. Shankha’s elder brother has a mass of 30kg. His brother is moving slower with a velocity of 2m/s. Shankha collides to his brother. Then both of them keep going down the hill as one unit. Calculate the resulting velocity of Shankha.
Solution:
Given,
M1= 20kg
M2= 30kg
V1= 5m/s
V2= 2m/s
Thus, after Shankha collides, the combined velocity of Shankha and his brother is 3.20m/s.
Problem 2:
Shankha driving a 20000 kg truck and travelling eastwards at a speed of 10m/s. He hit the rear end of a 1400kg car at the stop signal. The collision caused both vehicles to stick together. What is the final momentum of the vehicle?
Solution:
Given,
Mt = 20000kg
Mc= -1400kg
Vt =10m/s
Vc = 0m/s
Formula : Momentum P = MV
According to the conservation of momentum Pi = Pf
(MV)t+(MV)c = (Mt+Mc)V
(20000×10)(1400×0)=(20000+1400)×V
20000/3400 = V
V=5.8m/s
Thus, after collision Shankha’s truck and car striking together will move with a speed of 5.8m/s.
Frequently Asked Questions – FAQs
Is momentum conserved in the case of an inelastic collision?
Is Kinetic energy conserved in an inelastic collision?
No, kinetic energy is not conserved in an inelastic collision.
What is a collision?
A collision is an event in which two or more objects exert forces on each other for a short interval of time.
A car hitting a tree is an example of which type of collision?
What are the types of collision?
- Inelastic collision
- Elastic collision
Hope you have got a brief knowledge of inelastic collision, formulas, terms, examples and applications. For a better understanding of collision, do read the related articles and answer the practice questions.
Related Physics Concepts
| Elastic And Inelastic Collisions In One And Two Dimensions |
| Law Of Conservation Of Linear Momentum |
| Kinetic energy |
| Newton’s Second Law Of Motion And Momentum |
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