# Elementary question on car crashes and momentum

• Matt G
In summary, when two cars crash into each other, their momentum is transferred into the damage of the vehicles. Although kinetic energy is related to momentum, it does not account for the loss of momentum in this scenario. The momentum of the cars can be represented as vectors to better understand the forces acting on them. Under specified conditions, momentum cannot be created or destroyed.
Matt G
When two cars crash into one another they generally come to a stop, yet we are told momentum cannot be created or destroyed. Where did their momentum go? It seems like the kinetic energy went into the damage in the vehicles but apparently that has nothing to do with momentum?.

Thanks Matt

Can you write down their initial momentum? What forces are acting on the cars and what effect might they have on the momentum of the cars?

Sorry but it would just confuse me if I did. It seems like an abstract question and not one about a particular case

Matt G said:
yet we are told momentum cannot be created or destroyed.
Under specified conditions.

Matt G said:
Sorry but it would just confuse me if I did. It seems like an abstract question and not one about a particular case
If you insist on accounting for the lost momentum, this is the most meangful way of doing it.

Draw it as vectors and it becomes clear...

Matt G said:
Sorry but it would just confuse me if I did. It seems like an abstract question and not one about a particular case
It may confuse you, but we can work through that. The point here is to help you solve the problem.

## 1. What is momentum?

Momentum is a measure of an object's motion and is defined as the product of its mass and velocity. It is a vector quantity, meaning it has both magnitude and direction.

## 2. How does momentum relate to car crashes?

In a car crash, the momentum of the vehicles involved is a crucial factor in determining the severity of the collision. The greater the momentum of a vehicle, the more force it will exert on another object upon impact.

## 3. What is the conservation of momentum?

The law of conservation of momentum states that in a closed system, the total momentum before a collision is equal to the total momentum after the collision. This means that the total momentum of all objects involved in a car crash will remain constant, even if the direction or speed of individual objects changes.

## 4. How can the momentum of a car be calculated?

The momentum of a car can be calculated by multiplying its mass (in kilograms) by its velocity (in meters per second). The formula for momentum is: momentum = mass x velocity.

## 5. How can momentum be reduced in a car crash?

The momentum of a car can be reduced in a collision by decreasing its speed or by increasing the time it takes for the car to come to a stop. This can be achieved through the use of safety features such as seatbelts, airbags, and crumple zones, which help to absorb some of the car's momentum and reduce the force of impact on the passengers.

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