Types of Collisions explained with animation

Engineering Easy

6 Sept 202104:55

Summary

TLDRThis script explores collisions, detailing how they involve the transfer of momentum and kinetic energy between objects. It distinguishes between elastic and inelastic collisions, using examples like pool and car crashes to illustrate the concepts. Elastic collisions conserve both momentum and kinetic energy, as seen in pool, while inelastic collisions, like car crashes, conserve momentum but lose kinetic energy, converting it into heat and causing damage. The script emphasizes the conservation laws governing these interactions.

Takeaways

💥 Collisions occur when objects come into contact, resulting in the transfer of momentum and kinetic energy.
🏓 Collisions are common in sports like baseball, basketball, and pool, where objects interact.
🔄 In a collision, the net momentum of a system (objects involved) is conserved, meaning it remains the same before and after the collision.
🎱 Elastic collisions are those where no kinetic energy is lost, and no damage or heat is generated; pool is a close example of this.
🏒 In an elastic collision, both momentum and kinetic energy are conserved, as seen when a cue ball hits a resting ball in pool.
🚗 Inelastic collisions involve the conservation of momentum but loss of kinetic energy, often resulting in heat and damage.
💢 In inelastic collisions, objects may become entangled or stuck together, as exemplified by a car crash.
🚘 The conservation of momentum can be calculated using the equation \( m_1v_1 = (m_1 + m_2)v_f \), where \( m \) is mass and \( v \) is velocity.
🌟 Real-world collisions are rarely perfectly elastic due to factors like friction, air resistance, and gravity.
📐 Understanding collisions involves considering the conservation of both momentum and kinetic energy, and how they apply in different scenarios.

Q & A

What is the definition of a collision?
-A collision is an event where two or more objects come into contact with each other, resulting in a transfer of momentum and kinetic energy.
What is an example of a collision in everyday life?
-Examples of collisions in everyday life include hitting a baseball, bouncing a basketball, or playing pool.
What is the significance of momentum in collisions?
-In the absence of external forces, the net momentum of objects before a collision equals the net momentum after the collision, which is a principle known as the conservation of momentum.
What are the two types of collisions mentioned in the script?
-The two types of collisions mentioned are elastic collisions and inelastic collisions.
How is an elastic collision defined?
-An elastic collision is defined as a collision in which no kinetic energy is lost, no damage is done to the objects involved, and there is no generation of heat.
Why are real-world collisions not perfectly elastic?
-Real-world collisions are not perfectly elastic because various forces such as friction, air resistance, and gravity come into play, affecting the conservation of kinetic energy.
How does the game of pool represent an elastic collision?
-Pool tables and billiard balls are designed to reduce the effects of friction, resulting in collisions that closely resemble ideal elastic collisions.
What happens to the cue ball when it hits a resting eight ball in a game of pool?
-When the cue ball hits a resting eight ball, it transfers all of its momentum and kinetic energy to the eight ball, causing it to move, while the cue ball comes to a rest.
What is an inelastic collision?
-An inelastic collision is a type of collision where momentum is conserved, but kinetic energy is lost, often resulting in the creation of heat and damage to the colliding bodies.
How do objects behave after an inelastic collision?
-After an inelastic collision, the objects involved often become entangled or stuck together, as seen in a car crash where the vehicles become mangled and stuck together.
How is the conservation of momentum demonstrated in a car crash scenario?
-In a car crash scenario, the conservation of momentum is demonstrated by the fact that the total momentum before the collision is equal to the total momentum after the collision, even though the vehicles become stuck together and their speeds change.
What is the final velocity of the combined mass of two cars after a head-on collision if they had equal mass and car A was moving at 10 meters per second?
-After a head-on collision with equal mass cars, the final velocity of the combined mass is half the initial velocity of car A, which is 5 meters per second.

Outlines

00:00

💥 Collision Dynamics

This paragraph introduces the concept of collisions, explaining that they occur when objects come into contact and transfer momentum and kinetic energy. It distinguishes between elastic and inelastic collisions, with the former being idealized in games like pool where friction is minimized, and the latter involving loss of kinetic energy and potential damage to objects, exemplified by a car crash. The paragraph emphasizes the conservation of momentum in both types of collisions, using the cue ball and eight ball in pool as an example of an elastic collision, and a theoretical car crash scenario to illustrate an inelastic collision.

Mindmap

Keywords

💡Collisions

Collisions refer to the events where two or more objects come into contact, leading to a transfer of momentum and kinetic energy. In the context of the video, collisions are central to understanding how energy and momentum are transferred or conserved during interactions. Examples from the script include hitting a baseball, bouncing a basketball, or playing pool, all of which involve collisions.

💡Momentum

Momentum is a vector quantity that represents the product of an object's mass and its velocity. It is a key concept in the video as it is conserved in collisions, meaning the total momentum before a collision equals the total momentum after the collision, assuming no external forces. The script illustrates this with the example of a cue ball hitting a resting eight ball in pool.

💡Kinetic Energy

Kinetic energy is the energy possessed by an object due to its motion, calculated as one-half the product of the object's mass and the square of its velocity. The video discusses how kinetic energy is either conserved or lost in collisions. In elastic collisions, kinetic energy is conserved, while in inelastic collisions, some kinetic energy is lost, often converted into heat or used to cause damage.

💡Elastic Collisions

Elastic collisions are those in which both momentum and kinetic energy are conserved, meaning no energy is lost and no damage is done to the objects involved. The video uses the game of pool as an example of near-ideal elastic collisions, where the billiard balls are designed to minimize friction, leading to efficient transfer of momentum and kinetic energy.

💡Inelastic Collisions

Inelastic collisions are characterized by the conservation of momentum but not kinetic energy, resulting in some energy being lost, typically as heat or through damage to the objects. The video provides the example of a car crash, where the cars become entangled and lose kinetic energy, which is converted into other forms of energy such as heat and sound.

💡Conservation of Momentum

The conservation of momentum principle states that the total momentum of a closed system remains constant if no external forces act upon it. This principle is fundamental to the video's discussion of collisions, as it is used to explain the outcomes of both elastic and inelastic collisions. The script demonstrates this with a car crash scenario, where despite the loss of kinetic energy, momentum is conserved.

💡Friction

Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact. The video mentions that in an ideal scenario, like in a game of pool, friction is minimized to approximate elastic collisions. However, in real-world situations, friction can affect the outcome of collisions, causing energy loss.

💡Air Resistance

Air resistance, also known as drag, is the force that opposes the motion of an object through the air. The video script notes that in the real world, air resistance is one of the forces that make perfectly elastic collisions unlikely, as it can dissipate kinetic energy.

💡Cue Ball

The cue ball is the ball used by a player to strike other balls in games like pool and billiards. In the video, the cue ball is used to illustrate the transfer of momentum and kinetic energy during collisions, particularly in the context of elastic collisions where it transfers all its energy to the eight ball, coming to a rest.

💡Eight Ball

The eight ball is a specific ball in the game of pool, often used as a target ball. The video uses the eight ball to demonstrate how momentum and kinetic energy are transferred during collisions. It can receive momentum from the cue ball, either coming to rest or being set in motion, depending on the conditions of the collision.

💡Head-On Collision

A head-on collision occurs when two objects collide directly towards each other. The video describes a scenario where the cue ball and the eight ball collide head-on, resulting in the exchange of momentum and kinetic energy, with both balls bouncing off in opposite directions.

Highlights

Collisions happen when two or more objects come into contact, causing a transfer of momentum and kinetic energy.

The net momentum of both objects before a collision equals the net momentum after the collision, if no external forces are involved.

There are two types of collisions: elastic and inelastic collisions.

An elastic collision is one where no kinetic energy is lost, no damage is done to the objects, and no heat is generated.

Real-world elastic collisions are rare due to forces like friction, air resistance, and gravity.

Pool tables and billiard balls represent a near-ideal elastic collision, reducing the effects of friction.

When a cue ball hits a resting eight ball, it transfers all its momentum and kinetic energy, coming to rest while the eight ball moves.

If two balls collide head-on at the same speed, they bounce off each other with the same momentum in opposite directions.

In an inelastic collision, momentum is conserved but kinetic energy is lost, often resulting in heat generation and damage.

Bodies involved in inelastic collisions often become stuck together, such as in car crashes.

In an example of a car crash, two cars with equal mass collide, causing them to get mangled and stuck, with some energy converted into heat.

After an inelastic collision, the momentum is conserved, and the wreckage moves at half the initial speed due to the doubled mass.

The final velocity after the car crash is calculated using the conservation of momentum equation.

Elastic collisions conserve both momentum and kinetic energy, whereas inelastic collisions conserve momentum but lose kinetic energy.

Kinetic energy loss in inelastic collisions results in heat generation and material deformation, as illustrated by the car crash example.