What is an unbalanced force?

Answered by Jason Smith

An unbalanced force, as defined by Newton’s Laws of Motion, refers to a force that causes a change in the motion of an object. To understand this concept more deeply, let’s break it down step by step.

Newton’s First Law of Motion states that an object at rest will stay at rest, and an object in motion will continue moving in a straight line at a constant velocity, unless acted upon by an external force. This means that if there are no forces acting on an object, it will either remain stationary or continue moving with the same speed and direction.

However, if an unbalanced force is applied to an object, it will result in a change in its motion. This force can cause the object to start moving if it was initially at rest, or it can change the speed or direction of an object that was already in motion.

Let’s consider a simple example to illustrate this. Imagine a car parked on a flat road. The car remains at rest because the forces acting on it are balanced. The force of gravity pulling it down is countered by the normal force exerted by the ground, and there is no net force to cause a change in motion.

Now, if we push the car from behind with a certain force, let’s say by applying pressure on the gas pedal, we create an unbalanced force. This force overcomes the static friction between the tires and the road, causing the car to start moving. The unbalanced force in this case is the force exerted by the engine, which is greater than the frictional forces opposing motion.

Once the car is in motion, if we continue to apply a constant force, the car will continue to move at a constant speed in the same direction. The force we apply is balanced by the frictional forces and air resistance, resulting in no net force acting on the car. This is an example of a balanced force.

However, if we suddenly apply a greater force in the opposite direction, such as slamming on the brakes, the forces become unbalanced again. The force applied by the brakes exceeds the force of friction between the tires and the road, causing the car to decelerate or stop. In this case, the unbalanced force is responsible for changing the car’s motion.

It’s important to note that an unbalanced force can also change the direction of an object’s motion without changing its speed. For instance, if you’re swinging a pendulum, the force you exert on it at the extreme ends of its swing changes its direction, causing it to swing back and forth.

An unbalanced force is one that causes a change in the motion of an object. It can make an object start moving, change its speed, change its direction, or bring it to a stop. Understanding unbalanced forces helps us comprehend how objects respond to external influences and how they move and interact in the world around us.