physics paper2💜

• Magnetic materials


  • Iron
  • Steel
  • Nickel
  • Cobalt
• There is always a force of attraction between magnets and magnetic materials
• Magnetic field


  The region around a magnet where a force acts on another magnet (or magnetic material)
• The strength of a magnetic field depends on the distance from the magnet
• The field is strongest at the poles
• Magnetism and Electromagnetism
• Magnetic Fields
• ABOX
• Force


  Any push or pull
• Types of forces

  • Contact forces (when objects are physically touching)
  • Non-contact forces (like magnetism, electrostatic forces, gravity)
• Contact forces

  Normal force, friction, air resistance, tension
• Resultant force

  The net force acting on an object when multiple forces are present
• Finding resultant force

  1. Add vectors (considering direction)

  2. Use Pythagoras/trigonometry if forces are at right angles
• Balanced forces

  Forces that add up to zero, meaning the object will not accelerate
• Scalar


  A quantity with magnitude but no direction
• Vector


  A quantity with both magnitude and direction
• Scalar quantities


  • Distance, speed, mass, weight
• Vector quantities

  • Displacement, velocity, acceleration, force
• Weight


  The force due to gravity acting on an object, calculated as mass * gravitational field strength
• 1 kg of mass on Earth has a weight of 10 N
• Lifting an object at constant speed

  The upward force must equal the weight of the object
• Work done


  Energy transferred by a force, calculated as force * distance moved
• Hooke's Law

  Force = spring constant * extension, for elastic objects
• Moment


  A turning force, calculated as force * perpendicular distance to pivot
• Balanced moments mean an object will not turn
• Pressure


  Force per unit area, calculated as force / area
• Pressure in liquids

  Pressure = depth * density * gravitational field strength
• Gas pressure

  Due to collisions of gas particles with surfaces, increased by more particles, smaller volume, higher temperature
• Velocity

  Speed with direction, measured in m/s
• Acceleration

  Rate of change of velocity, measured in m/s^2
• Acceleration due to gravity is 9.8 m/s^2
• Newton's First Law

  An object's motion is constant if the net force is zero
• Newton's Second Law

  Force = mass * acceleration
• Newton's Third Law

  For every action force, there is an equal and opposite reaction force
• Momentum


  Mass * velocity, a measure of how hard it is to stop an object
• In a collision, total momentum is conserved even if kinetic energy is not
• Doubling your speed quadruples your braking distance because your car needs to lose all of its kinetic energy which is equal to half MV squared
• If you double the velocity, kinetic energy goes up by a factor of 4
• If you triple your speed, kinetic energy goes up by a factor of 9
• Factors that affect thinking distance

  • Distractions
  • Alcohol
  • Drugs