Newton`s Laws

Sir Isaac Newton was an English mathematician, physicist and astronomer who lived in the late 1600s. He is considered to be one of the most influential scientists of all time. Newton proposed the law of universal gravitation as well as the three basic laws of motion, which have influenced the study of physics for over 300 years.

Newton’s first law is also known as the law of inertia. This law 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. Inertia is an object’s resistance to a change in motion. For example, when a car brakes, a passenger’s body will tend to move forward due to inertia. A seatbelt provides an opposing force to this inertia.

Newton’s second law states that the acceleration of an object depends on the mass of the object and the net force affecting the object. When the same amount of force is exerted, an object with smaller mass accelerates faster than an object with larger mass. If the amount of force on an object is increased, then the acceleration will increase.

The equation that describes Newton’s second law is acceleration equals net force divided by mass. In this example, the cart has a force of 200 N and a mass of 40 kg. The acceleration is equal to 5 m/s2. Rearranging this equation to net force equals mass times acceleration is useful when you need to find the amount of force that is affecting an object.

Netwon’s third law states that for every action, there is an equal and opposite reaction. This is a simple way of saying that when one object exerts a force on another object, the second object responds with a force in the opposite direction. For example, when air is released from a ballon, the balloon is pushed in the opposite direction.