As we already know, it takes a force to move a stationary object. When a force moves something a distance, work is done. Work is measured in joules (J). In other words, force * distance = work when force = weight.
Energy is the ability to do work.
Kinetic energy is energy an object has due to motion. Moving objects have kinetic energy because they are moving. Potential energy is energy an object stores up or is not using. It has the potential to become kinetic.
Gravitational potential energy is potential energy due to an object’s position. Elastic potential energy is potential energy due to compression or expansion of an elastic object. Chemical potential energy is potential energy stored within the chemical bonds of an object.
As the song said, energy that is in motion is kinetic, and energy that is being stored or not used is potential. The example of the boulder waiting at the top of the mountain was gravitational potential energy because of its position on the mountain. Stretching the rubber band and holding it was an example of elastic potential energy because of the expansion of the elastic object. The energy that gasoline has stored up is an example of chemical potential energy.
The six general forms of energy are chemical, mechanical, thermal, electrical, light and nuclear.
Chemical energy is, as we already know, potential energy stored in chemicals, like gasoline. Mechanical energy is acquired or released by moving objects, like a thrown baseball or the turning blades of a windmill. Thermal energy is the motion of molecules and results from friction. Rubbing your hands to warm them up on a cold day is thermal energy.
Light energy is electromagnetic energy and different amounts of it to make different colors of light. Microwaves and lamps use light energy. Electrical energy is the moving of electrons. TVs and computers use electrical energy. Nuclear energy is energy stored in the nucleus of an atom.
Each of the six forms of energy can be converted to different forms and back again because energy is neither created nor destroyed.
An example of energy transformations: Thermal energy from boiling water was converted into mechanical energy when it was blown against wind turbine blades. Later, it was converted to electrical energy when the turbine blades spun, and was converted into light energy to light a lamp.
S&EP: SP4: Analyzing and interpreting data
This week, I used a Gizmo to explore roller coaster physics. I could change the height of the track, the weight of the car and the speed of the car to see what combinations would allow the car to break an egg at the end of the track. After changing the track’s height and the car’s weight and speed, I determined that the factors of speed and mass of the car seemed to determine if the car would break the egg. I constructed graphs to see the changes in the final speed after changing the heights of the track. The graphs helped me see the relationship between the heights of the track, the final speed and the height lost.
XCC: Cause and Effect
Changing factors like the speed and weight of the car can cause the car to break the egg or not. If the car was heavier, would it crack or break the egg even if the track wasn’t very high? If a tall track and a lighter were combined, would the egg break? I had to consider these things while doing the exercise because, when building a roller coaster, these factors will be important to think of to successfully be able to build a working coaster.
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