Chemical Energy
Energy stored in food, fuels or batteries - released through chemical reactions
Kinetic Energy
Energy stored in a moving object
Gravitational Potential Energy
Energy stored in a object lifted against gravity
Thermal Energy
Energy stored in hot or warm objects - the hotter the object, the more energy it has stored
Elastic (Strain) Energy
Energy stored in a squashed or stretched object
Electrostatic Energy
Anything with electric charge that is attracting or repelling another electric charge
Nuclear Energy
Atomic Nuclei have energy in the store can be released in nuclear reactions
Magnetic Energy
Anything magnetic that is interacting with another magnet
What is a System
A single object or a group of objects
What is a Closed System
A system where neither matter not energy can leave or enter
How can energy be transferred between stores
- Electrically
- Mechanically (lifting, pushing, pulling)
- By Heating
- By Light or Sound
- By Radiation
Equation for Kinetic Energy
Kinetic Energy (J) = 0.5mass(Kg)(speed)2(m/s)
Equation for Elastic Potential Energy
Elastic Potential Energy (J) = 0.5 * Spring Constant (N/M) * (Extension)2 (m)
What is Extension
when an object increases in length
What is Compression
when an object decreases in length or is squashed
Equation for Extension
Force (N) = Spring Constant (N/M) * Extension (m)
What is the Spring Constant?
Measure of the stiffness of a spring up to its Limit of Proportionality or Elastic Limit
The higher the Spring Constant, the stiffer the spring
What is the Limit of Proportionality?
Refers to the point beyond which an object cannot return to its original state - Hooke’s Law no longer applies
Specific Heat Capacity
The energy required to raise the temperature of 1Kg of a substance by 1C
C(J/KgC)
Specific Heat Capacity Equation
C = Energy (J) / Mass * Temperature Change
Design a method for an experiment with an aim to measure specific heat capacity of a metal
- Place the immersion heater into the slot at the top of the metal block
- Put the thermometer into the smaller slot
- Insulate the block by wrapping it with wool
- Record the stating temperature of the block
- Connect the heater to the power supply and turn it off after ten minutes
- Record the ending temperature then calculate the temperature change
- Repeat with different layers and different types of insulation
Energy Transfer Equation
Energy Transfer = Potential Difference * Current * Time
E = VIt
Work Done Equation
Work Done = Force * Distance
Work Done Equation when lifting
Work Done = Weight * Height
