1. GED Physical Science

2. Heat Heat is the flow of energy from a cold object to a warmer one.
Heat can be transferred by convection, conduction, or radiation

3. Transfer of heat Conduction- Transfer of heat through direct contact
Convection- Heat transfer through hot particles rising and cool particles falling
Radiation- Hot particles moving away from a reaction (like a fire).

4. Transfer of Heat

5. Heat in Reactions
Endothermic reactions absorb heat from surroundings. Examples: melting ice, evaporating liquid
Exothermic reactions give off heat. Examples: fire/combustion, condensation of liquids

6. Potential and Kinetic Energy
Kinetic energy is energy of motion
When an object is in a high place it has potential energy because of gravity
When it gains speed as it falls it converts potential energy to kinetic energy.
Photo: University of Richmond

7. Chemical Energy
Chemical energy is potential energy that could be converted to other types or energy by chemical reaction
Chemical energy of food can be converted to kinetic energy (movement) by cells in the body
Combustible materials contain chemical energy that is given off when they burn

8. Photo: TheDailyNathan
Mechanical Energy
Sum of potential and kinetic energy
Remains constant: potential energy is converted to kinetic energy and back.
Photo: TheDailyNathan

9. Sources of Energy: The Sun
Heat energy radiates from sun and is absorbed in solar panels
Method of energy production that reduces pollution
Sustainable, but reliant on sunlight

10. Sources of Energy: Fossil Fuels
Oil, Coal and Natural Gas are mined or drilled and burnt, producing energy
Fossil Fuels may not be sustainable because there is a finite amount
Fossil fuels produce pollution

11. Sources of Energy: Nuclear
Splitting an atom (nuclear fission) gives off heat in a reaction and the energy is harnessed
Sustainable, but does produce some nuclear waste
Threat of accidents (Chernobyl/Fukushima)

12. Waves Waves transfer energy
Electromagnetic waves transfer energy by vibration of electric and magnetic fields
Water waves transfer energy by moving particles of water
Sound waves are movement of particles transmitting sound

13. Parts of a Wave Wavelength: Distance between waves
Amplitude: Height of waves
Frequency: How many waves occur in a time frame
Higher wavelength means lower frequency.

14. Electromagnetic Spectrum
image: Simon Baier

15. Forces in Physics
Speed: Distance traveled in a period of time (magnitude of velocity)
Velocity: Speed moved in a direction
Acceleration: rate of increase of velocity
Momentum: mass of an object times the velocity. A large object has more momentum than a small one moving at the same velocity

16. Collisions Collisions are a transfer of momentum
When vehicles in motion collide, a change in momentum of one vehicle is met by a change in momentum of the other vehicle.

17. Newton’s Three Laws
1. Objects in motion stay in motion unless an external force is applied (law of inertia)
2. Force is equal to mass times acceleration (F=ma)
3. Every action has an equal and opposite reaction.

18. Gravity Physical bodies attract each other
Gravity on Earth is why things fall and have weight
Falling objects all accelerate at the same rate
Acceleration due to gravity is about 9.8 m/s2

19. Photo: Richmond Times-Dispatch
Work
When a force does work, it acts on a body and moves (or displaces) it
Work is measured in joules
Work equals force times displacement (W=fd)
Photo: Richmond Times-Dispatch

21. Structure of matter Atom is the smallest unit of matter
Atoms consist of a nucleus with protons and neutrons surrounded by a field of electrons
Atoms group together to form molecules
image: Fastfission

22. States of Matter Solid, liquid, gas and plasma
States change when temperature changes
As states of matter change molecules get further apart and move around more easily

23. Density The amount of mass a substance has per its volume (D=m/V)
In liquid or gas form, less dense substances float on more dense substances

24. Chemical Equations
Show a chemical reaction using chemical abbreviations
2HCl + 2Na -> 2NaCl + H2
2 atoms hydrochloric acid (HCl) react with 2 atoms sodium (Na) to create 2 atoms salt (NaCl) and Hydrogen (H2)
Nothing is wasted- everything on one side is on the other
Sometimes energy is given off

25. Solubility
Ability for a substance (the solute) to dissolve into another substance (the solvent)
Once dissolved, a solution is formed
Increasing heat of the solvent allows more of the solute to dissolve- like dissolving sugar in tea