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.