Science 🌸

• Key structure of the lungs include the trachea, bronchi,alveoli and the capillary network surrounding the alveoli
• The right ventricle pumps blood to the lungs
• The left ventricle pumps blood to the body
• Blood consists of plasma,red blood cells,white bloood cells,and platelets
• The three types of blood vessels are arteries,veins,and capillaries
• Aerobic resperation:glucose +oxygen->carbon dioxide +water
• Anaerobic respiration: glucose -> lactic acid
• Coranory heart disease is an example of a non-communicable disease
• Fatty materials build up and blocks coronary arteries and can lead to a heart attack treatment include lifestyle changes stents and statins faulty heart valves make the heart less efficient at pumping blood .replacement valves can be mechanically or biological
• A drug is a substance that has an effect on the body
• There are two types of drug, medicinal and recreational
• Cancer results from uncontrolled cell division forming tumors (beningn or malignant)
• Scientists have identified various lifestyle and genetic risk factors for cancer
• • Energy stores:
  • Magnetic
  • Internal(thermal)
  • Chemical
  • Kinetic
  • Electrostatic
  • Elastic potential
  • Gravitational potential
  • Nuclear
• • Energy pathways:
  • Mechanical
  • Electrical
  • Heating
  • Radiation
• Work is the measure of energy transferred when a force moves an object
• Work done(J)=force(N) × distance(m)
• Kinetic energy(J) =0.5 × mass(kg) × speed(m/s)²
• Gravitational potential energy (J) =mass(kg) × gravitational field strength (N/kg) × height(m)
• Power(W) =Energy transferred (J) ÷ time(s)
• Non renewable energy resources: fossil fuels (coal,oil nd gas),nuclear
• Renewable energy resources: bio-fuel ,wind ,hydroelectricity ,geothermal , th tides,the sun and water waves
• The national grid is a system of cab,es and transformers linking power stations to consumers
• Step-up transformers are used to increase the potential difference and increases effciency
• The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area
• A direct current (D.C) flows in the same direction. An alternating current (A.C)is constantly changing direction
• Mains electricity is an AC, frequency of 50 Hz and potential difference of 230V
• Brown live wire carries current to the appliappliance . Blue neutral wire completes the circuit . Yellow and green earth wire can carry current safely if a fault develops
• The fuse breaks the circuit if a fault in an appliance causes too much current to flow
• Circuit symbols

  
• Electric power is the rate at which energy is transferred by an electric pathway
• Power(W)= current(A) × potential difference(V)