hitting eachother

In this picture the red ball collided into the purple ball in a bouncy collision. In Physics we are learning about collisions and the conservation of momentum. When an object hits another object the momentum is conserved. This type of collision is called an inelastic collision. The collision in the picture shows a two-kilogram ball hitting a stationary one-kilogram ball. The red ball hit the purple ball and glanced off to the side. The purple ball moved straight back. This collision is a perfect example of a two dimensional collision.

potential energy

Since we are learning about energy I thought I should make my journal about energy. In the picture, my camera case is at rest on top of the garbage can. Even though the camera case is not moving it has different amounts of potential energy depending where you want to set the reference line. If you compare the high of the camera case to the ground, it has potential energy. If you want to compare the high of the case with the high of the trashcan then it has no potential energy. Potential energy is measured by the mass times the acceleration of gravity times the height of the object. If the case were to fall to the ground, the potential energy in the case would turn into kinetic energy. All the potential energy will turn into kinetic energy when the case hits the ground. Kinetic energy is calculated by half the mass times velocity squared. Many objects around the house have potential energy.

About the class

I think physics this year has been fun and challenging. The concepts of physics are hard to understand and the textbook can be difficult at times. I have a hard time understanding by myself. I need someone else to describe or teach me the new concepts. Classes and labs in physics are fun and keep me entertained. I am stressed about all my classes and this year feels like I am swamped by homework.

Inertia

In this picture, Newton’s first law of inertia is acting upon my car. My car is at rest because according to Newton’s first law objects at rest like to stay at rest. Right now there is gravity and normal force acting upon the car. Gravity pulls the car down at a rate of 9.8 m/s. There is an equal normal force pushing up on the car making the car stay on the ground. If I tried to push the car it would be hard because of the inertia of the car. The weight of the car is a lot so the inertia of the car is a lot. This means that the car wants to stay at rest. If the car was traveling at a constant speed, the car will want to stay at that constant speed.

Today my dad was trimming our hibiscus bush in our backyard. As he cut the branches off the bush, he tossed them to the ground. Seeing the branches fall got me thinking about the acceleration of gravity. The acceleration of gravity is always –9.8 m/s2. When my dad released the branch from his hand, the branch accelerated at –9.8m/s2 until it hit the ground. I also watched my dad throw multiple branches of different sizes and they fell to the ground at the same time because they have the same acceleration. I did not know that I could find physics in my backyard.

physics 1

Today I was watching football and saw physics in motion. In football physics is everywhere. In the picture, the defensive player is tackling the receiver. The receiver was accelerating forward for fifteen yards then stopped and cut to his right to catch the ball. The receiver changed his velocity because he changed the direction and speed he was traveling. After he caught the ball, he accelerated forward for one yard and one second until the defender stopped him who was accelerating backwards. After the abrupt stop, the receiver went backwards for two yards until he was pushed out of bounds. In that one play the receiver accelerated, changed his velocity. The total displacement of the receiver resulted in a fourteen-yard gain and a first down for his team. In that pay the ball also went through acceleration and change in velocity. When the ball was released from the quarterback’s hand the ball accelerated and went forward down the field to the receiver. The receiver caught the ball and the ball went through a larger negative acceleration.