Mock Revision

• What is a force?

  A push or pull on an object
• What are the two types of forces?

  Contact and non-contact forces
• What is an example of a contact force?

  Pushing a door
• What is an example of a non-contact force?

  Magnetism
• What is the significance of electrostatic repulsion in contact forces?

  It explains why contact forces occur
• What is a normal contact force?

  Force exerted perpendicular to a surface
• How can forces be represented?

  With vectors showing direction and magnitude
• What does the length of a force vector indicate?

  The magnitude of the force
• What is a resultant force?

  The overall force acting on an object
• How do you find the resultant force when two forces act in opposite directions?

  Add the vectors, making one negative
• What is the resultant force if one force is 5 N to the right and another is 2 N to the left?

  3 N to the right
• How do you find the resultant force when vectors are at right angles?

  Use Pythagoras' theorem
• What is the formula for calculating the resultant force using Pythagoras' theorem?

  $R =$$\sqrt{F_1^2 + F_2^2}$
• What does it mean if forces are balanced?

  They add up to zero
• What is Newton's first law of motion?

  An object will not change velocity without a resultant force
• What is a scalar quantity?

  A quantity with only magnitude
• What is the difference between displacement and distance?

  Displacement includes direction, distance does not
• What is weight?

  The force due to gravity on an object
• How is weight calculated?

  Weight = mass × gravitational field strength
• What is the gravitational field strength on Earth?

  9.8 N/kg
• What is the weight of a 1 kg mass on Earth?

  10 N
• What must be true for forces to be balanced when lifting an object?

  The upward force equals the weight
• What is the equation for work done?

  Work done = force × distance moved
• What does work done represent?

  Energy transferred by a force
• How can gravitational potential energy be calculated?

  GPE = mass × G × height
• What does Hooke's law state?

  Force = spring constant × extension
• What is the unit for spring constant?

  Newtons per meter
• What happens to an object that stretches elastically?

  It returns to its original shape
• What does it mean if force and extension are directly proportional?

  Doubling one doubles the other
• What is the significance of a straight line through the origin in a force-extension graph?

  It proves direct proportionality
• What is a systematic error in measurement?

  An error that consistently affects results
• What is a random error in measurement?

  An error that varies unpredictably
• What is the formula for the energy stored in a spring?

  Energy = $\frac{1}{2} k x^2$
• What happens to kinetic energy when an object is released from a spring?

  It gains kinetic energy in an ideal system
• What is a turning force?

  Force applied to create rotation
• How is moment calculated?

  Moment = force × distance to pivot
• What is the unit for moment?

  Newton meters
• What does it mean if moments are balanced?

  No rotation occurs
• What is the principle of moments?

  Moments clockwise equal moments anticlockwise
• How is speed calculated?

  Speed = distance / time