Newtons First and Second Law

• What are Newton's first and second laws of motion about?

  They describe motion and forces acting on objects
• What does Newton's first law state about resultant force?

  A resultant force is needed to change motion
• What happens to a stationary object if the resultant force is zero?

  The object remains stationary
• What happens to a moving object if the resultant force is zero?

  It continues moving at the same velocity
• What does Newton's second law state about non-zero resultant force?

  It causes the object to accelerate
• If a particle has unbalanced forces acting on it, what direction will it accelerate?

  In the direction of the larger force
• What can happen to an object when it accelerates to the right?

  It can start moving, speed up, or slow down
• How is acceleration defined in terms of velocity and time?

  Acceleration is change in velocity over time
• Why does the moon accelerate even with constant speed in circular motion?

  Its direction is constantly changing
• What force acts on the moon to keep it in orbit?

  The gravitational pull of the Earth
• What does the equation $F =$$ma$ represent?


  Resultant force equals mass times acceleration
• If a particle has a mass of $0.25 \text{ kg}$ and experiences a resultant force of $12 \text{ N}$, what is its acceleration?


  $48 \text{ m/s}^2$
• What is inertia?

  The tendency of an object to maintain motion
• How does an object's inertial mass relate to changing its velocity?

  It measures difficulty in changing velocity
• How do you calculate inertial mass?

  By dividing force by acceleration
• What does a large mass indicate about inertia?

  It requires a large force to change velocity
• How does inertia relate to Newton's first law?

  Inertia is the essence of the first law
• What are the key concepts of Newton's first and second laws of motion?

  • First Law: Resultant force needed to change motion
  • Second Law: Non-zero resultant force causes acceleration
  • Inertia: Tendency to maintain current motion
• What are the effects of acceleration on an object based on its initial motion?

  • Stationary: Starts moving in the direction of acceleration
  • Moving right: Speeds up
  • Moving left: Slows down or stops
  • Change in direction: Velocity changes without speed change
• What is the relationship between force, mass, and acceleration?

  • Resultant force is equal to mass times acceleration
  • Larger force results in larger acceleration
  • Inertial mass measures resistance to acceleration