CP2

• What is the force that pulls us towards the Earth?

  Gravity
• What is 'drag' another name for?


  Air resistance or water resistance
• Name two quantities that are vectors.

  • Force
  • Velocity
  • Acceleration
  • Displacement
• What are balanced forces?


  Forces of the same size in opposite directions
• What do we call the forwards force produced by an aeroplane's engine or propeller?

  Thrust
• What word describes both the speed and direction of movement of an object?

  Velocity
• What is the name for a single force on an object with the same effect as all the forces combined?

  Resultant
• How do we describe the forces on an object when the force in one direction is bigger than the force in the other?


  Unbalanced
• Two forces on an object are in the same direction. How do we calculate the resultant force?


  Add
• Two forces on an object are in opposite directions. How do we calculate the resultant force?


  Find the difference between them
• What is the name for the force on an object that acts in the same way as all the other forces combined?

  Resultant
• Give two examples of vector quantities.

  • Velocity
  • Force
  • Acceleration
  • Displacement
  • Weight
  • Momentum
• Give two examples of scalar quantities.


  • Speed
  • Mass
  • Distance
  • Energy
• What are the units for force?


  Newtons
• What is acceleration?


  Change in velocity - note, not change in speed
• What does the length of a force arrow on a diagram represent?


  Size of force
• An aeroplane has thrust of 2000 N and drag of 1800 N. What is the resultant?


  200 N forwards
• Air resistance on a cyclist is 20 N and friction is 5 N. What is the total force trying to slow the cyclist down?


  25 N backwards
• Name a vector quantity that changes as a car drives at constant speed around a roundabout.


  Velocity
• What are unbalanced forces?


  Forces of different sizes in opposite directions
• What is the direction of the resultant force on a car that is speeding up?


  Forwards
• What is the direction of the resultant force on a bicycle that is slowing down?


  Backwards
• How does a sideways resultant force affect the velocity of a moving object?


  Changes its direction
• How can the pilot of an aeroplane make the plane gain speed upwards?


  Increase the lift/upwards force
• How do balanced forces affect the velocity of a moving car?


  The car continues with the same velocity
• You pedal harder on a bicycle. What happens?


  You accelerate/get faster
• What is the name of the force that makes objects move in a circular path?

  Centripetal
• What provides the centripetal force for a car going around a roundabout?


  Friction
• What are the forces on a moon orbiting around a planet?


  Gravity acting towards the planet
• In which direction does centripetal force act?


  Towards the centre of the circle
• Why is the force of gravity greater on a lorry than on a car?


  Larger mass
• What are the units for acceleration?


  Metres per second squared, m/s²
• How is acceleration calculated from a change in velocity?


  Velocity change / time
• Is acceleration a vector or scalar quantity?


  Vector
• Name a force that accelerates objects downwards.

  Gravity/weight
• Why is the resultant force accelerating a car usually less than the force provided by its engine?


  Air resistance and/or friction
• Name one force that usually has to be taken into account when working out the resultant force on a moving object.

  Drag or friction
• When will a resultant force act to slow a car down?


  When backwards forces are greater than forwards ones
• How can friction act to make a car speed up?


  Between tyres and road
• How can friction act to make a car slow down?


  In brakes