Impact Force: Does Energy Absorption Affect Driver?

[Miraj Kayastha]

Suppose a car crashes with a tree. When it crashes the tree applies a force known as impact force.

Does the impact force apply equally to the driver and the car OR since the impact force is also used to crush the car does the force decrease when it reaches the driver?

So, does force decrease as energy is absorbed?

 

[Drakkith]

Different parts of the car (including the driver) experience different amounts of force based on the time it takes for them to decelerate to a stop. One of the things incorporated into car design is to make the car crumple and extend the time it takes to bring the vehicle to a stop. Safety features such as airbags and seat belts perform the same function for the driver. However, all that kinetic energy has to go somewhere, and generally it goes into deforming the car. Note that whether the car is designed with all these safety features or not, the kinetic energy is still absorbed. Car design just makes it so that it's spent in ways that protect the driver and passengers of the vehicle.

So no, the force doesn't necessarily decrease as energy is absorbed. It's reduced by decreasing the acceleration.