Newton's first law states that an object will remain at rest or in constant motion in a straight line unless acted upon by an external force. The second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The third law states that for every action, there is an equal and opposite reaction.
One example of Newton's second law is a car accelerating on a straight road. The force of the engine pushes the car forward, and the mass of the car determines how quickly it can accelerate. A lighter car will accelerate faster than a heavier car with the same amount of force.
A closed system is one in which there is no exchange of matter with its surroundings, but there can be an exchange of energy. An open system, on the other hand, allows for both the exchange of matter and energy with its surroundings.
To calculate the net force on an object, you must first determine all the individual forces acting on the object. Then, add the forces together using vector addition. The resulting sum is the net force on the object.
Equilibrium in a system refers to a state in which the net force and net torque on an object are both equal to zero. This means that the object is either at rest or moving at a constant velocity without any external forces acting on it. In other words, the forces and torques acting on the object are balanced, and there is no change in its motion.