There are four fundamental laws of physics: the law of conservation of energy, the law of conservation of momentum, the law of conservation of angular momentum, and the law of conservation of charge. These laws are based on experimental evidence and have been tested to great precision. They are considered to be fundamental because they are not derived from any other laws of physics.
The law of conservation of energy states that energy can neither be created nor destroyed, only converted from one form to another. For example, when you drop a ball, the gravitational potential energy it has at the top of its arc is converted into kinetic energy as it falls. When the ball hits the ground, the kinetic energy is converted into sound and heat energy.
The law of conservation of momentum states that the total momentum of an isolated system remains constant. Momentum is a measure of the motion of an object and is equal to the product of its mass and velocity. For example, when you throw a ball, the ball’s momentum is equal to the product of its mass and velocity. When the ball hits the ground, the ball’s momentum is transferred to the ground.
The law of conservation of angular momentum states that the total angular momentum of an isolated system remains constant. Angular momentum is a measure of the rotation of an object and is equal to the product of its mass, radius, and angular velocity. For example, when you spin a top, the top’s angular momentum is equal to the product of its mass, radius, and angular velocity. When the top slows down, its angular momentum is transferred to the air around it.
The law of conservation of charge states that the total charge of an isolated system remains constant. Charge is a measure of the electric property of an object. For example, when you rub a balloon on your hair, the balloon acquires a negative charge. The negative charge on the balloon is equal to the positive charge that is transferred to your hair.
These four laws of physics are the foundation of all of physics. They are the basis for our understanding of the physical world and have been used to make many important discoveries.