Physics chapter 2.2 year 3 2024

• Force


  A push or pull that can change the motion of an object
• You cannot see or feel forces that are exerted on other people or objects, you can only see the change caused by the force
• Forces can change an object in two ways

  • Elastic change (e.g. pushing against a trampoline)
  • Plastic change (e.g. shooting a bullet at an apple)
• Types of forces


  • Muscular strength
  • Resistance
  • Spring forces
  • Gravity
  • Magnetic forces
  • Van der Waals force
  • Normal force
  • Friction force
• Dynamometer


  Measures forces using a spring, graduated in newtons, for large (stiff spring) and small forces (flexible spring)
• Determining the force of gravity on an object


  Multiply the mass by 9.8
• Drawing forces


  • Magnitude (length of arrow)
  • Direction (direction of arrow)
  • Application point (where the arrow starts)
• The ability of metals to conduct electricity is one of their characteristics
• Ionic compound


  Formed when an electron is transferred from a metal to a non-metal
• Molecular compound


  Made up of atoms sharing electrons and molecules bound together by covalent bonds
• Molecular compound chemical formula examples


  • BrINCLHOF
• Van der Waals force


  Attractive force between molecules that are very close to each other
• Cohesion


  Attraction between like substances, e.g. water molecules attracting each other
• When two forces are equal but act in opposite directions, the object is in equilibrium and nothing will happen to it
• Resultant force (or net force)


  The sum of all the forces acting on an object
• Resultant force is easy to determine when the forces are in the same line
• Van der Waals forces

  Stronger for larger molecules, making them more difficult to take apart
• Resisting forces


  • Air friction
  • Rolling friction
  • Sliding friction
• Newton's first law


  If the resultant of all forces is zero, the object is either stationary or moves at constant speed in a straight line
• If the direction of the resultant force is the same as the direction of motion

  The object's motion accelerates
• If the direction of the resultant force is opposite to the direction of motion


  The object's motion decelerates
• If the direction of the resultant force is perpendicular to the direction of motion

  Only the direction of motion changes
• Training programme


  Made for individual needs based on age, gender, fitness level and sport
• Key principles of training programme

  • Specificity
  • Overload
  • Progression
  • Reversibility
• Specificity


  Training must be matched to the needs of the sporting activity to improve fitness in the body parts the sport uses
• Overload


  Fitness can only be improved by training more than you normally do. You must work hard
• Progression


  Start slowly and gradually increase the amount of exercise and keep overloading
• Reversibility


  Any adaptation that takes place as a result of training will be reversed when you stop training. If you take a break or don't train often enough you will lose fitness
• Factors to consider when designing a training programme

  • Frequency
  • Intensity
  • Time
  • Type
• Frequency


  Decide how often to train
• Intensity


  Choose how hard to train
• Time


  Decide for how long to train
• Type


  Decides which methods of training to use
• Moderation


  Have rest periods, which allow the body to adapt. Overtraining → injury
• If you have the perfect frequency, intensity and time but hate the actual exercise then you'll never do it
• The ACSM guidelines are 3-5 times per week
• Limited in your schedule


  Choose your Intensity level, which will help determine how long your workout session should be. A higher intensity →more benefit (burning more calories in a shorter amount of time)
• To calculate MHR (how hard you should work your heart to develop aerobic or anaerobic fitness): 220 - age = MHR
• Aerobic fitness


  Steady and not too fast, the heart is able to supply enough oxygen to the muscles. Refers to cardiovascular fitness, which can be improved by working in the aerobic target zone, which is between 60-80% of the maximum heart rate (MHR). The aerobic threshold is reached at 60% of the MHR
• Anaerobic fitness


  Performed in short, fast bursts where the heart cannot supply enough oxygen to the muscles. Anaerobic training improves the ability of the muscles to work without enough oxygen when lactic acid is produced. Includes strength, power, and muscular endurance, can be improved by working in the anaerobic target zone, which is between 80-100% of the MHR. The anaerobic threshold is reached at 80% of the MHR. Anaerobic fitness is affected by oxygen debt, which is the amount of oxygen consumed during recovery