Types of energy

1.       Gravitational potential energy: Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s2. Since the zero of gravitational potential energy can be chosen at any point (like the choice of the zero of a coordinate system), the potential energy at a height h above that point is equal to the work which would be required to lift the object to that height with no net change in kinetic energy. Since the force required to lift it is equal to its weight, it follows that the gravitational potential energy is equal to its weight times the height to which it is lifted.

2.       Chemical energy: it is a form of potential energy. chemical energy is the energy involved in the bond formed between two atoms. Each bond within a chemical compounds involves different amounts of energy. When one of these bonds breaks,  a chemical reaction occurs and chemical energy is used. The bond is released and is either reused in forming new bonds with other atoms or enters the surrounding atmosphere as heat. You can’t see chemical energy or touch it, but you can see it released when reactions occur.

3.       Mechanical kinetic energy: The kinetic energy of an object is the energy which it possesses due to its motion.[1] It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body in decelerating from its current speed to a state of rest.

4.       Thermal energy: A specialized term that refers to the part of the internal energy of a system which is the total present kinetic energy resulting from the random movements of atoms and molecules. The ultimate source of thermal energy available to mankind is the sun, the huge thermo-nuclear furnace that supplies the earth with the heat and light that are essential to life.

5.       Sound energy: Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound vibrations cause waves of pressure which lead to some level of compression and rarefaction in the mediums through which the sound waves travel. Sound energy is, therefore, a form of kinetic energy; it is not contained in discrete particles and is not related to any chemical change, but is purely related to the pressure its vibrations cause.

6.       Elastic potential energy: Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched. According to Hooke's law, the force required to stretch the spring will be directly proportional to the amount of stretch.

Canon

Our new class assignment is to build an ethanol fueled canon. the challenge is to build a cannon that has the longest range. Before actually build it we have to first design it in order to achieve a longer range. In order to achieve that goal, some background research was needed. It was very hard to find background information about cannon because almost all the searching results are about the brand called Canon, but I was still able to pull something out.

According to research, there are basically two factors that can affect the range of the ethanol fueled cannon. The first factor is the angle of the barrel. Angle is a very important factor to maximize the range. Consider this, the energy given is about the same which is 3ml of ethanol, and we already know from projectile motion that gravitational force is the reason why cannon ball will fall. Therefore, if we threw a ball too high, the v_y factor will have a bigger value, therefore the maximum height may be very high, but the vx will be smaller because the energy is taken by vy. And if we threw a ball too low, the vx factor will be bigger but since the vy is smaller, the ball will land on the floor very soon. Therefore, 45°is the angle that can have the maximum range because all vectors are equal.

The second factor that can affect the range is the height of the cannon. As I mentioned above, angles that are below 45 degree have a bigger vx component, but due to the insufficient of vy, the ball will land on the floor very fast. But if the height of the cannon was increased, the vy component will increase too. Therefore, the ball will have a longer hang time and this will maximize the range.

4 types of Newton problems

Projectile motion

Physics behind roller coasters

Everyone should at least ride on a roller coaster once before he dies, to experience the excitements physics bring. You may question, why do I say physics? Aren’t the roller coasters driven by electricity? In fact, it is driven only using potential energy and kinetic energy.

Potential energy is the energy stored in an object or in a system due to its position in a force field or due to its configuration. For example, a text book will create a very laud sound when it is dropped on the floor. Where does that sound energy come from? Well, gravity gives energy to all objects on this planet, the higher the text book is from the ground, this greater the energy it is stored. Therefore, gravity is the driven force of the roller coaster. When the train is released from the top of the lift hill, gravity pulls it down. Potential energy is the greatest when it is at the highest point of the roller coaster, as is the lowest at the lowest point. Kinetic energy is the energy which it possesses due to its motion. As it slides downwards, the potential energy is converted into kinetic energy, because according to Einstein’s conservation of mass, energy cannot be created or destroyed, but it can be converted from one form to another. However, every roller coaster system will have friction force between the wheels and the rail, which is one of the major factors that cause the coaster to slow down.

How to add vectors

How to add vectors?

1.       Set positive axis (north east)

2.       Break vectors into x components and y components

3.       Calculate x and y by sin and cos

4.       Use Pythagorean theory to solve for R (a2 + b2 = c2)

5.       Use tan to solve the angle of R

deriving equation 3 and 4 from graph