The First Law of Motion
Newton’s first law of motion states that “An object will remain at rest or will continue moving in a straight line with uniform velocity unless it is acted upon by an external force or constraint”. This law is also known as “inertia” and can be demonstrated by a simple experiment. You just need to have a bottle or jar, a playing card and a coin.
Experiment. Place the playing card on the top of the bottle opening as shown. Place the coin over the card such that the coin is positioned exactly on the top of the bottle’s opening. Now knock the card by striking it with your finger or by the flat end of a ruler. You will see that the card will always fall inside the bottle with the card falling elsewhere.
The Second Law of Motion
This second law states that “When force ‘F’ is applied on a body it produces acceleration ‘a’ which is parallel and directly proportional to the applied force ‘F’ and inversely proportional to the mass ‘m’ of the body”. The law is commonly represented as F = ma and can be demonstrated by the below given experiment.
Experiment. Take a hard rectangular wooden board with a smooth surface and attach a pulley at the center on one of its shorter side. Place a meter along the longer side of the board. Now take a piece of string with reasonable length and attach one end of it with a simple Dynamics trolley and the other end with some light weights. Move the string over the pulley such that the weights are now hanging down. As you increase the weight on the string, you will notice that there is some acceleration produced in the dynamic trolley which will be in the direction of the applied force or weight. Keep increasing the weights and mass on the trolley. If you take readings, it will be observed that;
F = ma.
The Third Law of Motion
This law is simpler of the other two from an understanding perspective and states; “To every action there is an equal reaction”. This can be demonstrated by means of a simple Balloon Powered Car.
Experiment. In the Balloon powered car, it can be observed that the air moves out of the balloon in one direction while the car moves in the opposite direction. This proves the concept of action and reaction.