Understanding and Sound of Newton’s laws 1, 2 and 3 equipped with Principles, Formulas (equations), Examples of Problems and Application of Newton’s laws 1 2 3☑️☑️
Complementing the previous article that discusses Pascal’s Law, then Ohm’s Law and Kirchhoff’s Law, this time the wikielektronika.com team will present one of the laws in the world of electrical physics, namely Newton’s Law.
Many theories and laws in physics are applied in everyday life. One of them is Newton’s laws. Newton’s law is a law that explains the relationship between the force that applies to an object and the motion it causes.
Definition of Newton’s Laws
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Understanding Newton’s Law is the basic law of classical mechanics (displacement) which describes the relationship of force to changes in the motion of an object. Based on its formulation, Newton’s laws are classified into 3, namely Newton’s Law I, Newton’s Law II, and Newton’s Law III.
As the name implies, the discoverer of Newton’s law is a physicist and mathematician from England named Sir Isaac Newton. This scientist is also the discoverer of Newton’s law of gravity. But this law is different from the law of gravity which discusses the attraction of the earth or gravity.
In that era, Sir Isaac Newton worked in many areas of mathematics and physics. He developed the theory of gravity in 1666 when he was only 23 years old. In 1686, he presented his three laws of motion in a book “Principia Mathematica Philosophiae Naturalis.”
As previously described that Newton’s laws are divided into 3 types, namely Newton’s laws 1, 2 and 3, where the sound of Newton’s laws for each is different and its application is different. For details you can see in the review below.
Newton’s Law 1
Illustration of Newton’s law 1 via : geeksforgeeks.org
Newton’s Law 1 defines that an object will move straight and orderly or only stand still if its resultant force is equal to zero. Based on this law it is known that objects will tend to maintain their position.
This law is also called Inertia, which is any object that will remain at rest if it does not get a force, then the object also tends to move straight in order. From this law it is known that objects that are initially stationary will remain stationary and objects that move also tend to remain in motion.
The law of inertia was first formulated by Galileo Galilei for horizontal motion on Earth and later generalized by Rene Descartes. Then the theory of the Law of inertia was deduced by Galileo through his experiments that used the ball rolling down in an inclined plane.
Newton’s Law 1
The sound of Newton’s law 1 states that an object that has a resultant force equal to zero (ΣF = 0), then the object will remain at rest, and an object in motion will still move at a constant speed in a straight line unless an unbalanced force is applied.
That is, an object will not start moving unless there is an external force acting to push it. Once the object moves, it will not stop or change its speed until there is a force acting on it once again.
An object will maintain a constant speed. If the speed is zero, then the object remains stationary. If an external force acts on the object, the speed will change according to the force exerted from outside.
Formula of Newton’s Law 1
Via : praxilabs.com
In mathematical notation, the formula of Newton’s law 1 is ΣF = 0, where ΣF is the total force. So if the object is at rest then v = 0 m / s, while if the object moves straight regularly then v = constant.
Two conditions that can be described in the formula of Newton’s law 1 are as follows:
- Stationary Object: When the object is at rest its velocity (v= 0) and acceleration is zero. Therefore, the object remains stationary.
- Moving Objects: When an object moves, velocity is not equal to zero (v ≠ 0) while acceleration (a = 0) equals zero. Therefore, the object will continue to move at a fixed speed and have the same direction.
Examples of Newton’s Law Problems 1
- A pack of chicken meat with a mass of 1 Kg hangs on the scale strap. If g = 10 m/s2 , then the amount of tension on the rope is . . . . . .
Discussion:
ΣF= 0T-w = 0T = wT = mgT = 1 Kg. 10 m/s2T = 20 N
So, the tension force on the rope acting on such meat scales is 20 Newtons.
- A hollow iron bar with a mass of 5 Kg (weight w = 50 N) depends on the rope tied to the construction of the building. If the hollow iron is at rest, what is the tension on the rope?
Discussion:
ΣF = 0T – w = 0T – 50 = 0T = 50-0T = 50 N
So, the tension force on the rope acting on the hollow iron is 50 Newtons.
- An iron pipe with a mass of 20 kg is placed on a slippery inclined plane with an inclination angle of 30′. If the plumber wants to push the iron pipe up at a fixed speed, how much force should be exerted by the carpenter?
Discussion:
m = 20 kg
g = 10 m/s2
w = mg = 20 × 10 = 200 N
α = 30′
The thrust (F) exerted by the handyman must be able to compensate for the projection of gravity. So the equation is obtained:
ΣF = 0F – w sin 30′ = 0F – (200)(1/2) = 0F – 100 = 0F = 100 N
So, the force that the builder must exert on the iron pipe in order for it to move at a constant speed is 100 N.
Newton’s Law 2
Illustration of Newton’s law 2 Via: slidetodoc.com
Newton’s Law 2 is a quantitative description of the changes that a force can produce in the motion of an object. As we all know, the time rate of change in the momentum of an object is equal in magnitude and direction to the force imposed on it.
The momentum of an object is equal to the product of its mass and velocity. Momentum, like velocity, is a vector quantity, which has magnitude and direction. The force exerted on an object can change the amount of momentum or its direction or both.
Unlike the sound of the first law, the second law speaks of constant acceleration and force. The second law talks about the change in momentum (m * V) so that, at this point, we cannot separate how much mass changes and how much velocity changes.
The Sound of Newton’s Law 2
Newton’s Law 2 states that the acceleration of an object depends on the mass of the object and the magnitude of the force exerted. While the direction of acceleration is equal to the direction of the total force acting.
From this law it can be seen that the acceleration of an object depends on the mass of the object and the magnitude of the force exerted. The speed of an object will increase when you get the total force in the same direction as the direction of motion of the object.
Conversely, if the total motion is opposite to the direction of motion, the force will actually slow down the rate and even stop the motion of the object.
Formula of Newton’s Law 2
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In mathematical notation, the formula of Newton’s law 2 is ΣF = m*a , where ΣF = total force on the body (N), m = mass of the object (kg) and a = acceleration of the object (m / s2).
The formula of Newton’s law 2 defines force equal to the change in momentum (mass times speed) per change in time. Momentum is defined as the mass m of an object multiplied by its velocity V.
So that the equation ΣF = m*a is obtained from the equations ΣF = (m1 * V1 – m0 * V0) / (t1 – t0) and ΣF = m * (V1 – V0) / (t1 – t0). This relationship applies only to objects that have a constant mass.
The above equation tells us that an object subjected to an external force will experience acceleration and the amount of acceleration is proportional to the magnitude of the force. But the magnitude of the acceleration is always inversely proportional to the mass of the object.
Examples of Newton’s Law 2
- A Jeep car can produce a resultant force of 10000 Newtons. If the jeep is moving with an acceleration of 4 m/s2, what is the mass on the jeep?
Discussion:
ΣF = 10000 Na = 4 m/s2m = ….. ?
m = ΣF /am = 10000/4m = 2500 kg / 2.5 tons
So, the mass on such jeeps is 2.5 tons.
- An object with a certain mass (m1) is given a certain resultant force (F) that produces an acceleration of 20 m/s2. If the resultant force is applied to another (second) object with a certain mass (m2), an acceleration of 30 m/s2 is obtained. Determine: the ratio of m1 and m2 and also the acceleration generated by the force (F1) if m1 and m2 are combined!
Discussion:
# The force on object 1 with mass m1 has an acceleration of = 20 m/s2, so:
m1 = F1/a1m1 = F/ 20 m/s2
# The force F on object II with mass m2, produces acceleration a2 = 30 m/s2, then:
m2 = F2/a2 = F/30 m/s2m 1 : m2 = F/20 : F/30m1 : m2 = 1/20 : 1/30m1 : m2 = 1 x 60/ 20 : 1 x 60/ 20m1 : m2 = 3: 2
So the mass ratio between object 1 and object 2 is 3 : 2
# Then if the two objects are combined, then mass is obtained:
m = m1 + m2m = F/20 + F/30m = 3F + 2F/ 60m = 5F/60m = F/12
#Percepatan produced when two objects are combined is:
a = F/ma = F/(F/12)a = 12 m/s2.
So the combined acceleration between object 1 and object 2 is 12 m/s2.
- There is Table A with a mass of 8 kg placed on table B which has a mass of 12 kg. Then table B is pulled with a force (F) until both tables experience an acceleration of 2 m/s2. If suddenly beam A falls, then what is the acceleration on beam B?
Discussion:
mA = 4 kg
mB = 6 kga1 = 2 m/s2a2 = .….?
F = m*aF = (mA + mB) * a1F = (8 + 12) * 2F = 20 * 2F = 40 N
Substitution of Force (F) in the condition of the second table, so as to get:
F = mB*a240 = 12*a2
a2 = 3.4 m/s2
Newton’s Law 3
Newton’s law illustration 3 via: wired.com
The last discussion is Newton’s law3 which speaks of reaction action. The purpose of this reaction action is that if the object is given action, then the object will also give a force equal to the magnitude but in the opposite direction from the action force given.
The third law is also known as the law of action and reaction. This law is important in analyzing the problem of static equilibrium, where all forces are balanced, but it also applies to bodies moving in harmony or accelerated.
An illustrative example, a plate placed on the table applies a downward force equal to its weight on the table. According to the third law, the table applies the same and opposite style to the plate.
This force occurs because the weight on the plate causes the table to slightly change shape so that it pushes back the plate like a circular spring.
Newton’s Law 3
The sound of Newton’s law 3 states that when two objects interact, they apply a force to each other that is equal in magnitude and in opposite directions.
This means that every time there is action there will always be a reaction of the same magnitude and opposite directions, or two objects that have the same force but opposite directions.
Every time an object exerts a force on the second object, the second object exerts a force equal in magnitude and in the opposite direction on the first object.
Formula of Newton’s Law 3
Via : scientificsentence.net
In mathematical notation, the formula of Newton’s law 3 is F1 = – F2 or F action = – F reaction, where F1 is the action and F2 is the result of the reaction.
For example, if object A exerts a force on object B, object B also exerts a force equal in magnitude and in the opposite direction on object A. In other words, the force results from the action of the reaction that occurs on both objects.
Examples of Newton’s Law 3
- A bird flying with its wings produces a reaction action force. Determine the action-reaction pair that occurs in the bird!
Discussion:
Action Force: The thrust exerted by a bird’s wings against the air.
Reaction Force: The thrust of the bird that air exerts on the wings so that the fish can fly to move.
- A builder has a mass of 50 kg. Then the craftsman pushed the wall with a force of 250 Newtons. So the reaction force exerted by the wall against the handyman is. . . .
Discussion:
m = 50 kgF(action) = 250 NF(reaction) = ….?
F(action) = – F(reaction)250 = – F(reaction)F(reaction) = -250 N
Differences between Newton’s Laws 1, 2 and 3
| Kind | Formula | Sound | Application |
| 1. Newton’s Law 1 (Inertia) | ΣF = 0 | An object at rest remains at rest, and an object in motion remains in motion at a constant speed and in a straight line unless an unbalanced force is applied. | Kite motion when there is a change in cardinal directions |
| 2. Newton’s Law 2 (Force) | ΣF = ma | The acceleration of an object depends on the mass of the object and the magnitude of the force applied. | Aircraft motion resulting from aerodynamic forces, aircraft weight, and thrust |
| 3. Newton’s Law 3 (Action &; Reaction) | F1 = −F2 | Every time an object exerts a force on another body, the second object exerts a force equal in magnitude and in the opposite direction on the first object. | The ball rotates, the air is deflected to one side, and the ball reacts by moving in the opposite direction |
Examples of the Application of Newton’s Laws
The existence of this legal theory can be proven by various events that are found in everyday life. Unconsciously, some events that we experience in everyday life are one example of the application of Newton’s laws. Here are some examples of events in everyday life.
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Examples of the application of Newton’s Law 1 in everyday life
The first example of law-related events can be seen when riding a vehicle that is initially moving. When braked, the body of the person riding will be pushed forward.
Similarly, when you are in a stopped vehicle, when the vehicle that initially stopped then moves, the body of the person in it will tend to be pushed backwards.
Examples of Newton’s law 1 in everyday life can also be seen in the following events: The movement of the aircraft when the pilot changes the engine throttle setting, a model rocket is launched into the atmosphere and also the motion of the kite when there is a change in cardinal directions.
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Examples of the application of Newton’s Law 2 in everyday life
Next is an example of Newton’s law 2 that can be seen in everyday life can be seen when you are pushing a table. A table with a small mass and a table with a large mass will certainly produce different accelerations.
Pushing a table with a small mass can be faster than a table with a large mass. This theory proves the existence of a second law in the events of the driven table.
The application of the second law in everyday life can also be observed in aircraft movements resulting from aerodynamic forces, aircraft weight, and thrust.
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Examples of the application of Newton’s Law 3 in everyday life
The first example can be seen while rowing a boat. When rowing a boat, the rower will move the rowing tool backward, but the direction of motion of the boat is actually forward. It shows action and reaction.
The next example of application can be seen in the motion of a rotating ball, air is deflected to one side, and the ball reacts by moving in the opposite direction.
Furthermore, the movement of the jet engine generates thrust and hot exhaust gases flow out of the rear of the engine, and the thrust is generated in the opposite direction.
Also Read:Definition of Pascal’s Law
Thus was a brief and complete discussion of Newton’s laws 1, 2 and 3 and the events that describe each of these laws.
Newton‘s laws relating to the forces that apply to objects and their direction of motion can actually be observed in various events around us. After understanding this law, it is hoped that you can work on examples of problems related to these events.
