Unit 2: Mechanical energy

The idea that objects moving have energy that depends on their mass and speed.
The notion of stored energy or "potential energy"
Doing energy conservation as keeping the sum of all energies conserved, and how this is equivalent to looking at the changes in energy as done in unit 1.
The idea of equilibrium was introduced.

Kinetic energy (KE)
Energy associated with the movement of the object. We distingush between two main types of movement: rotational movement and translational movement.: KE_trans
The translational kinetic energy. It is the energy associated with moving the object as a whole. For an object of mass m and velocity v, the translational kinetic energy is KE_trans = mv²/2: KE_rot
The rotational kinetic energy. The faster an object rotates, the more KE_rot it has. A formula similar to the one above exists for KE_rot, but requires concepts we will not develop until Physics 7B.: Potential energy (PE)
Energy that is stored between systems. Comes in many different forms, depending on the systems in action.: PE_gravity
The potential energy for an object sitting in a gravitational field. PE_grav = mgy where m is the mass, g = 10 m/s² on Earth and y is the height above some arbitrary choice of y=0.: PE_mass-spring
The energy stored in a spring. This depends on a characterstic of the particular spring k (called the spring constant) and the distance from equilibrium y in the following way PE_mass-spring = ky²/2. Notice that it does not matter what sign the displacement from equilibrium is, the potential energy is still the same.

DL and FNTs 1-3 cover this material.

Physics 7 Underground notes