can an object be in equilibrium (the state in which the net force on an object is zero) if only one force acts on the object?
not unless that one force is zero
In order for an object to be in equilibrium, the net force acting on it must be zero. This means that the sum of all the forces acting on the object is balanced and there is no overall force causing it to accelerate. But can an object be in equilibrium if only one force acts on it?
To answer this question, we need to consider Newton's second law of motion, which states that the net force on an object is equal to the product of its mass and acceleration. Mathematically, it can be represented as F_net = m * a.
If only one force is acting on an object, we will have F_net = F, where F is the magnitude and direction of the force. For the object to be in equilibrium, F_net must be zero.
So, if only one force acts on the object, for it to be in equilibrium, that force must be balanced or canceled out by another force. This can occur when the single force is counteracted by another force of equal magnitude but opposite direction.
For instance, consider a book placed on a table. The weight of the book is pulling it downward with a force (F) due to gravity. In this case, the normal force exerted by the table on the book acts in the upward direction and has the same magnitude (F) as the weight of the book. These two forces balance each other, resulting in a net force of zero. Therefore, the object (the book) is in equilibrium, even though only one force (gravity) is acting on it.
In summary, while an object can be in equilibrium if only one force acts on it, it requires that the single force is balanced or countered by another force of equal magnitude but opposite direction.