Inertia and newton's third law

• What is inertia?

  The tendency for motion to remain unchanged
• What happens to objects at rest if no resultant force acts on them?

  They stay at rest
• What does an object's inertial mass measure?

  How difficult it is to change its velocity
• How can inertial mass be calculated using Newton's Second Law?

  Using the formula m = F/a
• What does Newton's Third Law state about forces between two interacting objects?

  They are equal and opposite
• What happens when you push a shopping trolley?

  The trolley pushes back against you
• Why do objects move if the forces they exert on each other are equal?

  Because the forces act on different objects
• What happens when skater A pushes skater B?

  Both skaters accelerate away from each other
• Why does skater A accelerate more than skater B?

  Because skater A has a smaller mass
• What is an example of Newton's Third Law in an equilibrium situation?

  A man pushing against a wall
• What forces act on a book resting on a table?

  The weight of the book and the normal force
• Why is the weight of the book and the normal force not an example of Newton's Third Law?

  They act on the same object
• What are the pairs of forces acting on a book resting on a table?

  The weight of the book and the normal force from the table
• What is the gravitational force acting on the book called?

  Weight
• What does the normal contact force from the table do to the book?

  It pushes up on the book
• What is an example of a pair of forces demonstrating Newton's Third Law in a car moving at constant velocity?

  The car's tires pushing back on the road
• What is the relationship between force, mass, and acceleration according to Newton's Second Law?

  • Force (F) equals mass (m) times acceleration (a)
  • Rearranged: m = F/a
• What are the key concepts of Newton's Third Law?

  • Forces are equal and opposite
  • Act on different objects
  • Examples include pushing and pulling interactions
• What is the difference between equilibrium forces and Newton's Third Law forces?

  • Equilibrium forces act on the same object
  • Newton's Third Law forces act on different objects