Forces & Motions

• What is the definition of force?


  A force is a push or pull acting on an object.
• How does force affect an object's motion?


  Force can cause an object to start moving, stop moving, or change its speed or direction.
• What is the definition of motion?


  Motion is the change in position of an object over time.
• What are the key points related to force and motion?

  • Force is measured in **Newtons** (N)
  • Motion is described by **displacement**, **velocity**, and **acceleration**
  • Forces can be **contact** (e.g., pushing a box) or **non-contact** (e.g., gravity)
• What happens when you kick a football?


  You apply a force that causes the ball to move, changing its position over time.
• How is force measured?


  Force is measured in Newtons (N).
• What are the two types of forces?

  Contact forces and non-contact forces.
• What is Newton's First Law of Motion?

  It states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
• What is inertia?

  Inertia is the property of objects to resist changes in their state of motion.
• What happens to an object at rest according to Newton's First Law?


  It tends to stay at rest unless acted upon by a force.
• What happens to an object in motion according to Newton's First Law?


  It tends to stay in motion unless acted upon by a force.
• How does Newton's First Law apply to a book on a table?

  The book will remain stationary unless a force, like a hand, moves it.
• What is the relationship between force, mass, and acceleration in Newton's Second Law?


  The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
• What is the mathematical expression of Newton's Second Law?

  $F =$$ma$
• How does pushing an empty shopping trolley differ from pushing a full one?


  The empty trolley accelerates more quickly than the full one when the same force is applied.
• What does it mean if an object has more mass when the same force is applied?


  It will have less acceleration.
• What is Newton's Third Law of Motion?


  For every action, there is an equal and opposite reaction.
• What does it mean that forces come in pairs according to Newton's Third Law?


  When one object exerts a force on another, the second object exerts an equal force back on the first object in the opposite direction.
• What happens when you jump off a boat?

  You push the boat backwards as you move forwards.
• How does a rocket launch demonstrate Newton's Third Law?

  The rocket pushes exhaust gases downwards, and the gases push the rocket upwards.
• What are the key points of Newton's Third Law of Motion?


  • Forces always come in pairs
  • These pairs are equal in magnitude but opposite in direction
  • The action and reaction forces act on different objects
• What is the relationship between mass and acceleration for a given force?


  Acceleration is inversely proportional to mass.
• What does Newton's Third Law of Motion state?

  For every action, there is an equal and opposite reaction.
• What happens when one object exerts a force on another object according to Newton's Third Law?


  The second object exerts an equal force back on the first object in the opposite direction.
• How does a rocket launch according to Newton's Third Law?

  A rocket pushes exhaust gases downwards, and the gases push the rocket upwards.
• What are some everyday examples of Newton's Third Law of Motion?


  • Jumping off a boat pushes the boat backwards
  • Walking pushes the ground backwards, and the ground pushes you forwards
  • Swimming pushes water backwards, and the water pushes you forwards
• What is gravitational force?


  The attraction between objects due to their mass.
• What is electromagnetic force?


  The force between electrically charged particles.
• What is normal force?


  The perpendicular force exerted by a surface on an object.
• What is tension?


  The force transmitted through a string, rope, cable, or wire.
• What is applied force?


  Any force applied to an object by another object or person.
• What is friction?


  The force resisting relative motion between surfaces in contact.
• What are the key types of forces?

  1. Gravitational force
  2. Electromagnetic force
  3. Normal force
  4. Friction
  5. Tension
  6. Applied force
• What is static friction?


  Static friction prevents objects from starting to move.
• What factors affect friction?


  • Surface roughness
  • Normal force
  • Material properties
• What is kinetic friction?


  Kinetic friction slows down objects already in motion.
• What are the effects of friction?


  • Allows walking without slipping
  • Wears down materials over time
  • Generates heat
  • Slows down moving objects
• How can friction be reduced?


  By using lubricants like oil.
• How can friction be increased?


  By making surfaces rougher or using special materials.
• What type of friction do you overcome when pushing a heavy bookcase?


  You initially overcome static friction.