Physics 3E

Physics 3E

1. Key Processes

   • KE = ½ mv
   • m = (2 × KE) ÷ v
   • v2 = (2 × KE) ÷ m
   • Unlike cars powered by fossil fuels, battery-driven cars don't have an exhaust pipe and so don't pollute the air around them
   • Electric cars, however have to be recharged using electricity generated at a power station. This means it causes pollution at the power station
   • Unlike fossil fuels, biofuels are renewable resources. In addition, their use may lead to an overall reduction in emissions of carbon dioxide because the growing plants absorb carbon dioxide from the atmosphere
   • Solar cells convert light energy into electrical energy. The electricity can be used to drive an electric motor in a car. However, although solar powered vehicles do not produce pollution when they are used, pollution is produced when they are made. However, their use may lead to an overall reduction in emissions of carbon dioxide
   • The fuel consumption and range of all vehicles depend on how much energy the vehicle can store, either in a fuel tank or in batteries. They also depend on factors such as whether the vehicle is: Driven uphill a lot, carrying large loads or not, driven at high speed, driven over rough road surfaces, and if the vehicle is driven with underinflated tyres

2. All moving object have Kinetic Energy

3. Cars can use fossil fuels, biofuels, and solar energy or be battery powered

4. Batteries need to be recharged; most electricity for this comes from fossil fuelled polluting power stations

5. Streamlining shapes can reduce friction forces and decrease fuel consumption

6. Fuel consumption of a vehicle can be affected by: - its speed, its KE, its shape, the driving style of the driver and the road surface

7. When the mass of a car is doubled, its KE is doubled

8. When the speed of a car is doubled, its KE & braking distance is quadrupled