PHY 121 is the first Introductory Physics course at Arizona State University. This Physics class is offered to engineering and other science and pre-professional majors. Not everyone can register for this class. You need to pass MAT 270 before enrolling in this class. PHY 121 has many concepts but below are the top 5 concepts you’ll be studying:

### 1) Mechanics

Mechanics generally includes kinematics and dynamics. In general, kinematics is the branch of Physics which studies the motion of bodies and system of bodies without knowing the mass of that object or the forces acting on it. On the contrary, dynamics is the complete inverse of kinematics. Dynamics is the branch of Physics which studies the motion of bodies and system of bodies with knowing the mass of that object or the forces acting on it.

### 2) Newton’s Law of Motion

One of the most interesting things studied in this course is Newton’s Law of motions. There are 3 laws of motions stipulated by Newton. Firstly, the law of inertia. Secondly, acceleration is produced when a force is acted on a mass and lastly, for every action, there is an equal and opposite reaction.

### 3) Conservation of momentum and energy

This law of conservation of momentum and energy is the most important and most used law in the field of mechanics. The law says that if there are no net forces on a system, then that system will have the same momentum, p = mv, at all times. In addition, if there are no external or internal forces acting in or on a system, then the energy of that system will remain constant.

### 4) Newtonian Gravitation

So the law of Newtonian Gravitation states that all the particles in the universe attract every other particle using some kind of force which is found out to be directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This law has been classified as a part of Classical Mechanics and is an important concept in PHY 121.

### 5) Simple Harmonic motion

Simple harmonic motion is defined as the oscillatory motion under a retarding force which is directly proportional to the amount of displacement from the initial position. It is very important to understand all the involved concepts in SHM (simple harmonic motion) because there might be few sums and projects based on SHM.

The above stated are the top 5 concepts studied in PHY 121. It is very important to know the concepts in a class before registering, as there might be few things which might not interest you. Hopefully, the above information helps you to know more about PHY 121. Happy Studying 🙂