Here's why:
* Friction opposes motion: Friction is a force that resists the relative motion of two surfaces in contact. It acts in the opposite direction to the motion.
* Decreasing acceleration: When two objects move against each other, friction acts to slow them down. This slowing down means their acceleration decreases.
Example: Imagine two cars colliding head-on. The impact force is initially very high, causing rapid acceleration/deceleration. However, as the cars crumple and surfaces rub together, friction kicks in. This friction acts to reduce the acceleration, ultimately bringing the cars to a stop.
Types of friction: There are different types of friction, including:
* Static friction: The force that prevents two surfaces from moving relative to each other when at rest.
* Kinetic friction: The force that opposes the motion of two surfaces sliding past each other.
* Rolling friction: The force that opposes the motion of a rolling object.
All of these friction forces play a role in decreasing the acceleration of objects moving against each other.
