# Newton’s Laws

When an apple fell on his head, Newton began to think about how things move. This led to the creation of Newton’s Laws, which you’ve probably heard of before. There are four laws altogether, including one about gravity. Let’s dig into each law and figure out what they mean and how they’re used in math. These laws are really important in the world of physics, so let’s get started!

## What is Newton’s first law?

Newton's first law of motion explains how things move and how they stay still. Basically, if nothing is pushing or pulling on an object, it will stay the way it is. This is called a state of rest. If an object is already moving, it will keep moving in the same direction and at the same speed unless something stops it.

For example, if you put a pen on a desk, it will stay there until you pick it up. But if you roll a ball across the floor, it will eventually slow down and stop because of friction.

However, if you roll a bowling ball down a lane, it will keep rolling for a long time because there is less friction. This is because the bowling ball is heavier and has more momentum.

Overall, Newton's first law helps us understand how objects move and why they stay still. It's the foundation for understanding how the world works!

## What is Newton’s second law?

Newton's second law of motion explains how force affects the way objects move. The more force you apply to an object, the faster it will move. But the bigger the object is, the harder it is to move. This is why it takes more force to push a car than a bicycle.

The mathematical formula for Newton's second law is force = mass x acceleration. This means that the force applied to an object is equal to its mass multiplied by its acceleration. The bigger the mass of the object, the slower it will accelerate.

For example, if you push a 5kg ball with a force of 150N for 2 seconds, it will accelerate at a rate of 30 m/s² and reach a speed of 60 m/s. If you push a 10kg ball with the same for the will at 15 m/s² and reach a speed of 30 m/s.

Another example is if you push a 15kg ball with a force of 150N for 4 seconds, it will accelerate at a rate of 10 m/s² and reach a speed 40 m/s. But if you push a 15kg ball with the same force for only 2 seconds, it will only reach a speed of 20 m/s.

Overall, Newton's second law helps us understand how force affects objects of different masses and how they move as a result. It's essential for understanding the world around us!

## What is Newton’s third law?

Newton's third law of motion explains how forces work in pairs. For every action, there is an equal and opposite reaction. This means that if one object exerts a force on another object, the second object will exert an equal and opposite force back on the first object.

For example, when you sit on a skateboard and throw a basketball forward, you will be pushed backward with the same force as the basketball was thrown. This happens because the force you exerted on the basketball is equal and opposite to the force the basketball exerted back on you.

Another example is a rocket. Rockets work by expelling gas particles due to combustion. According to Newton's third law, the rocket will experience an equal and opposite force to the force it exerts on the gas particles, which propels the rocket forward.

The conservation of momentum also comes into play with Newton's third law. Since force is equal to the rate of change of momentum, the momentum of the two objects will be equal and opposite as well. This means that the total momentum of the system remains constant, which is known as the conservation of momentum.

Overall, Newton's third law helps us understand how forces work in pairs and the conservation of momentum. It's a fundamental law of that applies to all objects whether're.

## What is Newton’s law of gravitation?

Newton's law of gravitational attraction is an essential aspect of our understanding of the forces acting on objects in the universe. When we connect this idea to Newton's second and third laws of motion, we can see how they work together to explain the behavior of objects under the influence of gravity.

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that the forces exerted by two objects on each other are always equal and opposite. The law of gravitational attraction fulfills this requirement, as the forces exerted by the two masses are equal and opposite.

Newton's second law of motion tells us that the acceleration of an object is directly proportional to the force acting on it and inversely proportional to its mass. When we apply this to the law of gravitational attraction, we can see that the acceleration of an object due to gravity depends on the mass of the object it is attracted to and the distance between them.

The principle of equivalence is also important in understanding the law of gravitational attraction. It states that the gravitational mass of an object is equal to its inertial mass. This means that the mass measuring the gravitational interaction is the same as the mass measuring the inertial properties of a body.

Overall, the law of gravitational attraction, along with Newton's second and third laws of motion and the principle of equivalence, helps us understand the forces acting on objects in the universe. From rockets launching into space to objects falling on Earth, these laws apply to all objects and have helped us understand the world around us.

## Newton’s laws: free-body diagrams

A free-body diagram is a sketch of only the object in question and the forces acting upon it. The object or ‘body’ is usually shown as a box or a dot. The forces are shown as thin arrows pointing away from the centre of the box or dot. The emphasis is on the forces, so they must be drawn accurately and to scale. It is important to label each arrow to show the magnitude of the force it represents. The type of force involved may also be shown.

Here is a very basic example of a free-body diagram. Note that it is not showing all the forces acting on the object (for example, you usually show the normal force and gravitational force acting on the object as well).

Free-body diagrams contain quantitative information needed to solve problems. System diagrams are only helpful to understand the problem and visualise it.

As a summary, Newton's laws of motion are fundamental principles of classical mechanics. The first law states that an object will remain in a state of rest or uniform motion in a straight line unless acted upon by an external force. The second law states that the net force acting on an object is equal to its mass times its acceleration. The third law states that for every action, there is an equal and opposite reaction.

Newton also formulated the first law of gravitational attraction, which is consistent with his laws of motion. A free-body diagram is a useful tool to illustrate the forces acting on an object and can help in analyzing its motion. These concepts are essential in understanding the behavior of objects in the universe and have practical applications in fields such as engineering and physics.

## Newton’s Laws

**What is Newton’s first law?**

Newton’s first law of motion states that a body continues in its state of rest or in uniform motion in a straight line unless acted upon by a force.

**What is Newton’s second law?**

Newton’s second law of motion states that a body acted upon by a force moves in such a manner that the rate of change of momentum in time equals the force.

**What is Newton’s third law?**

Newton’s third law of motion states that if two bodies exert forces on each other, these forces are equal in magnitude and opposite in direction.

**What is Newton’s law?**

There are three laws of motion. Newton’s laws of motion show the relationship between an object’s motion and the forces that act on it.