Energy

Students are Expected to Understand

How Work Transfers Energy

Measuring and Determining Mechanical Energy, Work, and Power

Principals Behind Energy Transformations and Conservation of Energy

Some Notes on Motion

• Work can be negative - (energy out) or positive + (energy in) to show the direction of energy transfer but not the direction of energy itself as energy is a scalar quantity

• Work can also be used to show energy transformation from one type to another, i.e. Potential turning into Kinetic Energy

• This unit focuses on Mechanical Energy which is a type of energy that combines both Potential and Kinetic Energy

• Potential Energy (PE) will assume that we're on Earth with a gravitational acceleration of g = -10 m/s² unless given otherwise

• Kinetic Energy (KE) is the energy of motion. Pay careful attention to the velocity in the equation KE = ½mv² as it has some interesting consequences

  • • It takes an exponentially greater amount (a much, much bigger amount) of KE to increase the velocity of an object

• Energy can be moved from one object into another but one can't really make it disappear - it just has to be placed elsewhere

• Generally, there's a finite energy to everything, including our own universe

• People frequently transform Kinetic Energy to Thermal Energy to stop moving via friction brake but now we're seeing more Kinetic Energy being transformed as stored electrical energy

• Perpetual motion machines can never exist due to 2nd Law of Thermodynamics as energy is continually lost to the environment around the machine