p10 - force and motion

• What does Newton's second law of motion state?

  Acceleration is proportional to resultant force
• How does a greater force affect acceleration?

  It results in greater acceleration
• What does inertia refer to in Newton's first law?

  Resistance to change in motion
• What are the key components of Newton's second law of motion?

  • Acceleration is proportional to resultant force
  • Acceleration is inversely proportional to mass
  • Force = mass × acceleration
• What is the relationship between mass, force, and acceleration?

  • Greater mass = smaller acceleration for same force
  • Greater force = greater acceleration for same mass
  • Inertial mass affects force needed for acceleration
• What is terminal velocity?

  Velocity remains constant with no acceleration
• What happens when an object reaches terminal velocity?

  It stops accelerating and maintains velocity
• What force pulls objects downwards towards the Earth?

  Gravity
• What is the force called that a person feels due to their mass?

  Weight
• What is the resultant force when a person first steps out of an airplane?

  It is equal to their weight
• What force acts in opposition to weight when falling?

  Air resistance
• How does air resistance affect a falling person?

  It slows them down by opposing weight
• What factors affect the size of air resistance?

  Surface area and velocity
• What happens to air resistance as a person falls faster?

  It increases
• What does the resultant force represent?

  Combination of all forces acting on an object
• What happens to the rate of acceleration as air resistance increases?

  It decreases
• What occurs when air resistance equals weight?

  Resultant force becomes zero
• What is the new terminal velocity when a parachute is opened?

  It is lower than the previous terminal velocity
• What happens when an object first starts falling?

  • Weight downwards is larger than air resistance upwards
  • Resultant force is downwards
  • Object accelerates towards the ground
• What occurs as an object accelerates and its velocity increases?

  • Air resistance increases
  • Resultant force decreases
  • Rate of acceleration falls
• What happens when a parachute is deployed during a fall?

  • Surface area increases
  • Air resistance increases
  • Resultant force becomes upwards
  • Object decelerates until new terminal velocity is reached
• What are the key points about terminal velocity covered in the video?

  • Weight pulls down, air resistance opposes
  • Resultant force determines acceleration
  • Terminal velocity reached when forces balance
  • Parachute alters terminal velocity
• What is stopping distance?

  Minimum distance required to stop a vehicle
• What is the formula for total stopping distance?

  Total stopping distance = thinking distance + braking distance
• What does thinking distance represent?

  Distance traveled during driver's reaction time
• What factors affect thinking distance?

  Speed of vehicle and reaction time
• How does speed affect thinking distance?

  Higher speed increases thinking distance
• What can increase a driver's reaction time?

  Being tired, drunk, or distracted
• What is braking distance?

  Distance taken to stop after brakes are applied
• What factors affect braking distance?

  Speed, mass of vehicle, and brake condition
• How does speed affect braking distance?

  Higher speed increases braking distance significantly
• What are the effects of road conditions on braking distance?

  • Wet or icy roads reduce friction
  • Worn tires decrease grip
• What are the different types of elasticity discussed in the video?

  Elastic and inelastic deformation
• What does the term 'spring constant' refer to?

  It measures stiffness of a spring
• What does Hooke's Law state about force and extension?

  Force is proportional to extension
• What is elastic deformation?

  Object returns to original shape after force removal
• What is inelastic deformation?

  Object does not return to original shape
• What is extension in the context of springs?

  Increasing length of a spring when stretched
• How can we measure the extension of a spring?

  By adding downward force and measuring length change
• What force acts on a spring due to its own mass?

  Weight acting downwards