There are many things we have learned in Physical Science this year, but the first and most important thing to know about science is hypothesis. A hypothesis is a possible explanation for the observation based on an educated guess. That is what all types of sciences are based on. Another extremely important term is Law: If a theory can withstand longstanding testing, a theory can become law. There are five fields of physical science: physics, chemistry, astronomy, geology, and meteorology, but in this course we only focused on physics. 

Units and systems measure how large or small things are. The metric system’s smallest unit is a millimeter. Then a centimeter, decimeter, meter, dekameter, hectometer, and finally a kilometer. The metric system is simple and easy to understand. For example, 1 meter equals 10 decimeters, and 1 decimeter equals 10 millimeters. There are four universal forces: The force of gravity, electromagnetic force, weak nuclear force, and strong nuclear force. 

Momentum of an object is the product of the object’s mass and its velocity. Calculating the momentum of an object is written as: P=mv. P stands for momentum, m is mass, and v is velocity. If you drop an object and it bounces back to you at the same height, the collision is perfectly elastic. Impulse is the product of the average force applied to a body and the time that it is applied to the body. Any body that experiences a change in momentum has had an impulse act upon it. Work is defined as the product of a force and the distance through which force moves an object. A simple machine is something that has a work input and a work output but whose output force is different from its input force. An example of a simple machine is a wedge. A wedge is similar to an inclined plane but in this case unlike an inclined plane a wedge moves.

Simple Harmonic Motion can be described as motion in which a body continuously repeats its motion because it has an outside force acting upon it. Temperature can be used to describe how hot or cold something is, or how hot or cold the outside air is. (F-32)x 5/9 is the formula for converting Fahrenheit to Celsius. In Celsius, 0 degrees is freezing, and in Fahrenheit it is 32 degrees. 

There are four laws of thermodynamics: the zeroth law, the first, second, and third laws. The First Law states: “The Heat put into a system is equal to the increase in the system plus the work done by the system.” When a substance goes from a lower energy phase to a higher energy phase it absorbs more energy. Electric potential is measured in volts. Volts is written as V. Rubbing a balloon on someone’s hair can result in a voltage of 5,000 V. Ohm’s Law states that the current through something is directly proportional to the voltage across the object and inversely proportional to the resistance of the object. 

Every single magnet on earth has a north and south pole. No matter how much you break a magnet it will still have a north and south pole. Wave motion can be used to describe all types of waves, like sound waves, and electromagnetic waves. Amplitude is the loudness of something. Period is the time it takes for an object to make one complete oscillation. Cyclical Frequency is the number of oscillations an object can make per one second (Hertz 1/s). Wavelength is the distance between two identical points in a wave after it has made one complete oscillation. Wave Speed is the speed at which a wave moves. Sound waves can pass through any medium. Sound requires a medium to pass through if it wants to move. Sound cannot travel through space because of its vacuum. 

The Speed at which sound travels depends on the medium that it is passing through. The amplitude and frequency don’t matter. The Speed is higher in liquids and gasses, though. Hard surfaces reflect sound and soft surfaces absorb it. When a sound travels it causes the frequency of the sound it creates to be higher in the direction it is traveling and lower in the opposite direction. When the waves overlap and form a V shaped wave, that wave is called a bow wave. When an object moves faster than the speed of sound it creates a shock wave. When the shock encounters someone, they hear a loud boom. A material is transparent to a frequency if the light can pass through it, while a material is opaque to a frequency of light if the light cannot pass through it. Most materials around us are opaque. That is most of the material we learned in Science. Science is one of the most important fields you can study in, and it is directly colorated with math. Most of Science was discovered through hypothesis, and without hypothesis we would not understand the physical world we live in.