when a truck pulls a trailer, the trailer and truck accelerate forward even though the action and reaction forces are the same size but are in opposite directions. why don't these forces balance each other out
They action and reaction forces are applied to diffent bodies. In this case, one is applied to the truck and the other is applied to the ground.
The two forcs DO cancel out when you are considering the complete Earth-truck system, together.
When a truck pulls a trailer, the trailer and the truck acclerate forward even though the action and reaction forces are the same size but are in opposite direction. Why don't these force balance each other
When a truck pulls a trailer, the trailer and truck accelerate forward even though the action and reaction forces are the same size but are in the opposite directions. Why dont these forces balance each other?
The forces between the truck and the trailer, known as action and reaction forces, do indeed balance each other out. However, when analyzing the motion of the truck and the trailer as a system, it is important to consider the individual forces acting on each object separately.
When a truck pulls a trailer, the truck exerts a forward force on the trailer. By Newton's third law of motion, the trailer exerts an equal and opposite force on the truck. Therefore, the two forces are balanced.
However, if we consider the force acting on each object individually, we see that they are not canceled out. The forward force applied by the truck on the trailer causes the trailer to accelerate forward. Similarly, the backward force applied by the trailer on the truck causes the truck to accelerate backward.
The reason the truck and trailer accelerate in the same direction is due to the difference in mass between the two objects. In this case, the mass of the truck is typically larger than the mass of the trailer. According to Newton's second law of motion (F = ma), when the same force is applied to objects with different masses, the object with the smaller mass will experience a greater acceleration. As a result, the trailer accelerates more than the truck, causing both objects to move forward.
Overall, the action and reaction forces may cancel each other out, but the individual accelerations of the truck and trailer are determined by their individual masses.