Energy & Work
- Energy is the capacity to do work, therefore:
Transfer of energy = Work Done
- This principle can be used to form mathematic equations for each type of energy
- The type of transfer of energy depends on the scenario
- The most common types of energy that are transformed between each other are:
Kinetic
- Kinetic is the work done by any object which is in motion
Ek = ½ mv2
- Where:
- m = mass (kg)
- v = speed of velocity (m s-1)
Gravitational Potential
- Gravitational potential is the work done against gravity when an object is lifted
Ep = mgΔh
- Where:
- m = mass (kg)
- g = acceleration due to gravity (m s-2)
- Δh = change in height (m)
Thermal
- Thermal (heat) is the work done on or by a system to transfer heat
E = mcΔT
- Where:
- m = mass (kg)
- c = specific heat capacity (J kg-1 K-1)
- ΔT = change in temperature (K or °C)
Elastic Potential
- Elastic potential energy is the work done in stretching or compressing an object
E = ½ Fx = ½kx2
- Where:
- F = stretching or compressing force (N)
- x = extension (or compression) (m)
- k = force constant (N m-1)
Nuclear
- Nuclear is the work done by nuclei during the processes of fusion and fission
E = Δmc2
- Where:
- Δm = mass defect (kg)
- c = speed of light