energy and forces

• The Law of Conservation of Energy

  energy is not created or destroyed, it just changes from one form to another form.
• What is renewable energy?

  Forms of energy that can be used over again after they are used
• What are the different Forms of Renewable Energy?

  1. Biomass
  2. Wind
  3. Solar
  4. Tidal
  5. Geothermal
  6. Hydroelectric
  7. Wave
• Benefits of Renewable Energy

  1. Non-renewable energy sources (coal, oil, gas & nuclear) are running out quickly.
  2. Renewable energy sources do not release as much carbon dioxide into the atmosphere. This reduces the rate of Global Warming.
• Geothermal

  Cold water is pumped under the ground into 'hot rocks'. The water is changed to steam and returns to the surface. Here it turns turbines that turn generators to make electricity.
• Wind Turbines

  Blades and turbines are placed at the top of tall towers. The wind turn the turbines to produce electricity. Most are found at the coast or on top of hills. They can be noisy, ruin the scenery and kill birds. Wind farms can take up large areas and land is cleared to build them (effecting wildlife).
• Tidal

  Dams are built across river estuaries. When the tide flows in gates are lowered to trap the water. When the water is released it flows through turbines producing electricity. Tidal 'barrages' have a negative effect on the environment. animals can no longer move in and out of the river estuary freely.
• Wave Power

  The motion of the waves can be used to produce energy. This is a method that has not been very successful due to the large amount of energy being difficult to harness.
• Biomass

  Biomass is energy that can be generated from animals and plants (wood) or their waste (e.g. slurry and sewage). If wood is burned, trees can be replanted to produce more wood. Animal waste (slurry & sewage) can be placed in a bio-digester to produce methane gas. This is burned producing electricity.
• Hydroelectric

  Water is trapped behind dams in river valleys high in the mountains (or built across large rivers). As the water flows downhill it turns turbines to produce electricity. Gravitational potential energy is changed into kinetic energy. Hydroelectric dams are built in areas with high rainfall.

  Disadvantages are that a large area needs to be flooded with water causing people to lose their homes, farmland to be destroyed and has a large impact on wildlife.
• What is Efficiency?

  It is the amount of useful energy produced by an object/machine compared to the total amount of energy taken in. Efficiency = Useful Energy / Total Energy Useful Energy = Efficiency x Total Energy Total Energy = Useful Energy / Efficiency
• What is stopping distance

  The stopping distance is the total distance it takes a vehicle to stop after the driver first sees a hazard. The stopping distance can be split into; the thinking distance and the braking distance.
• Thinking distance

  the distance the vehicle travels between the driver seeing the hazard and hitting the brake.It is effected by how quickly the brain processes the information - or your reaction rate.
• braking distance

  the distance the vehicle travels after the driver hits the brakes until the vehicle stops.It is effected by the condition of the road or vehicle.
• Factors effecting the Thinking distance.

  • Illegal Drugs
  • Legal Drugs (prescribed by your doctor)
  • Tiredness
  • Distractions (e.g. using a mobile phone)
• Factors effecting the Braking distance

  • Road Condition (e.g. potholes, mud on road, loose stones)
  • Weather Conditions (e.g. snow, ice, rain - reduce friction between the tyre and road)
  • Vehicle Condition (e.g. faulty brakes, worn brakes and 'bald tyres')
• Testing reaction time

  • Two people are required for the test
  • Pupil One holds the Ruler. Pupil Two places their thumb and index finger at the 0cm mark (ready to catch the ruler)
  • Pupil One drops the ruler (without telling Pupil Two) and stops the ruler as quickly as possible. Record the distance.
  • Reapet the test two more times and take an average distance (to make the teat more reliable).
• Fossil fuels

  Fossil Fuels were formed millions of years ago when living things (plants and animals) died and were covered in silt/mud/sediment/sand and gradually turned into coal, oil and gas. The carbon that was 'locked' under the ground is released to the atmosphere as carbon dioxide when fossil fuels are burned. This increases in carbon dioxide in the atmosphere leads to GLOBAL WARMING.
• The UK Government want to reduce the amount of petrol and diesel being burned by cars. They plan to achieve this in 2 ways.

  1. The sale of NEW petrol and diesel cars will be banned in 2030.
  2. By using more renewable fuels in cars and other vehicles - they are called BIOFUELS.
• What are Biofuels?

  Biofuels come from materials produced by living things. There are two main types of Biofuels;

  1. Biodiesel
  2. Gasohol
• 1. Biodiesel

  This is made from oils produced by plants e.g. sunflower oil or rapeseed oil.It completely replaces normal diesel.It is known as a SUBSTITUTE fuel.Some businesses currently use BIODIESEL to power their lorries e.g. Tayto
• Gasohol Produced when petrol is mixed with alcohol.The alcohol made by fermenting plant material (e.g. sugar cane and sugar beet)It is known as an EXTENDER fuel (because less petrol is used it extends the time petrol will last).Gasohol is very popular in Brazil.
• Advantages of BIOFUELS

  Reduce the amount of Carbon Dioxide entering the atmosphere - this reduces Global Warming
• Disadvantages of Biofuels

  Damage to the Environment - Forests are often cleared to produced more land to grow crops used to make biodiesel and alcoholLand used to grow food is often turned over to growing plants to produce biofuels.
• car and road safety

  Seat Belts-Stop the driver and passengers being thrown forward during a collision.

  Air Bags-Protects vehicle occupants during a collision by absorbing energy.

  Crumple Zones-Vehicles have specially designed 'crumple zones' to absorb some of the energy generated by the collision.

  Rigid Vehicle Cage-A frame is built around the vehicle and passenger 'cell' where the occupants sit.
• how to make roads safer

  Speed Limits-Safe speed limits are set for roads.

  Speed Cameras-Drivers caught speeding are issued with a fine or penalty points

  Traffic Calming-The are many traffic calming measures to slow traffic e.g. wider pavements, traffic islands etc.

  Speed Bumps-Vehicles must slow down to safely drive over the speed bump
• speed and distance time graphs

  Speed = Distance / Time Distance = Speed x Time Time = Distance / Speed

  Speed = m/sDistance = meters Time = seconds
• Kinetic - Moving Objects
• Light Energy - Produced by Luminous objects e.g. the Sun
• Electrical Energy - Present when a current flows
• Magnetic Energy - Present when a magnet is present
• Nuclear Energy - Present in the nucleus of an atom
• Chemical Energy - Stored in Chemical Bonds e.g. in fuel and food
• Gravitational Potential Energy - Energy when an object is off the ground
• Elastic Potential Energy - Energy when an object is compressed or Stretched
• Sound Energy - Produced by Vibrations e.g. the skin of a drum