Describe the motion under balanced forces.

Under balanced forces, an object either remains at rest or continues to move at a constant velocity.

In physics, the concept of balanced forces is fundamental to understanding motion. When forces acting on an object are balanced, it means that the net force, or the sum of all forces acting on the object, is zero. This state of equilibrium results in the object either remaining stationary or moving at a constant speed in a straight line. This is in accordance with Newton's first law of motion, also known as the law of inertia, which states that an object at rest tends to stay at rest, and an object in motion tends to stay in motion with the same speed and in the same direction, unless acted upon by an unbalanced force.

For instance, consider a book lying on a table. The force of gravity pulling the book downwards is balanced by the normal force from the table pushing it upwards. Since these forces are equal and opposite, they cancel each other out, resulting in a net force of zero. Consequently, the book remains at rest.

Similarly, if a car is moving at a constant speed on a straight road, the forces acting on it are balanced. The forward force provided by the car's engine is balanced by the combined effects of air resistance and friction between the tyres and the road. As these forces are equal and opposite, they cancel each other out, resulting in a net force of zero. Therefore, the car continues to move at a constant speed in a straight line.

However, it's important to note that if any additional force is applied to the object, the forces become unbalanced, and the object's state of motion will change. For example, if you push the book on the table, the forces become unbalanced, and the book will move. Similarly, if the car's engine provides more force or if the friction or air resistance increases, the car will either speed up, slow down, or change direction.

In conclusion, balanced forces are crucial in maintaining an object's state of motion, whether it's at rest or moving at a constant velocity.