# Physics: At a Glance

Many people fear the word physics. The idea that is formed is long equations just to describe the motion of a ball being thrown in the air. And well, that’s true. But it’s not as convoluted as many believe it to be. For the most part, physics can be summed up by three rules. Most have heard of these rules, which are also referred to as Newton’s Laws. These guidelines set up the very most basic rules for simple motion. Newton firstly began to think about the laws of gravity and motion when he was sitting under an apple tree, and watched an apple fall to the ground. Thus, the three laws were born.

The first law is pretty easy to understand. Newton states; “An object in motion stays in motion, and an object at rest stays at rest.” So, disregarding the fact that we live on earth and our gravity acceleration is 9.8 m/s/s, and object in motion in space will stay in motion and an object at rest will stay at rest with no outside forces acting upon the object. Outside forces would include gravity along with friction. Galileo Galilei, one of the most famous fathers of science in the seventeenth century. He found that if a ball rolled from the top of one slope to the top of another one, the initial and final heights would not equal each other, but the final height would be less than the initial. Without these restricting conditions on objects, things would move constantly and forever.

A deciding factor in whether if an object is in motion would be its inertia. This is an object tendency to resist forces. The inertia can be calculated using the objects mass. However, it’s found that the larger the mass, the larger the inertia, thus meaning the bigger chance the object has at resisting outside forces. I feel inertia is the most vague topic when it comes to discussing physics. Hopefully this video will be able to give a better understanding.

The second law is a little bit trickier than the first. This law breaks down the motion of an object further than the first law. It states that F = ma, or mass multiplied by the acceleration is the net force that the object has. So if an object on earth weighed 250 kg, and the acceleration is 9.8 m/s/s, the net force of the object as it is falling to the ground will be 2450 N. The abbreviation for the measurement of the force is called newtons.

The last law not only includes the motion of an object but also the activity of two objects whenever they collide. Newton states in his third law that for every action, there is an equal and opposite reaction. The forces from the first object are equal to the forces on the second object and are also opposite of these forces. They always come in pairs. For the types of interactions that objects have with each other are called collisions and are measured by impulses.

Impulses are just forces that act over a period of time. This can be found by calculating the change in velocity and multiplying it by the mass.

People are afraid of physics because of the startling numbers, the unidentified characters from the Greek alphabet that are normally used in equations. But it can be broken down to steps and explanations that everyone can understand.

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