5.4.11 Velocity-Time Graphs

• What is the purpose of velocity-time graphs in GCSE Physics?

  They help in understanding and analyzing an object's motion.
• What insights do velocity-time graphs provide?

  They show how velocity changes over time and can determine acceleration and displacement.
• What is a Velocity-Time Graph?

  • A graph that plots velocity against time.
  • Shows how the velocity of an object changes over a period.
• What do the axes of a Velocity-Time Graph represent?

  • X-Axis (Horizontal): Represents time (seconds).
  • Y-Axis (Vertical): Represents velocity (meters per second, m/s).
• What does the slope of a velocity-time graph represent?

  The slope represents the acceleration of the object.
• What does a positive slope on a velocity-time graph indicate?

  A positive slope indicates positive acceleration (speeding up).
• What does a negative slope on a velocity-time graph indicate?

  A negative slope indicates negative acceleration (deceleration or slowing down).
• What does a zero slope on a velocity-time graph indicate?

  A zero slope indicates constant velocity (no acceleration).
• What does the area under a velocity-time graph represent?

  • The area under the graph represents the displacement (distance traveled) of the object.
  • Can be calculated using different shapes:
  • Rectangle: Displacement = Velocity × Time
  • Triangle: Displacement = 1/2 × Base × Height
• How do you calculate displacement if the graph forms a rectangle?

  Displacement = Velocity × Time.
• How do you calculate displacement if the graph forms a triangle?

  Displacement = 1/2 × Base × Height.
• What does a horizontal line on a velocity-time graph indicate?

  • Indicates constant velocity.
  • The slope is zero (no acceleration).
  • Displacement can be found by calculating the area of the rectangle formed.
• If the velocity is 10 m/s and time is 5 seconds, what is the displacement for constant velocity?

  Displacement = 50 meters.
• What does a straight line with a constant slope on a velocity-time graph indicate?

  • Indicates constant acceleration.
  • The slope represents the acceleration.
  • The area under the line can be calculated using the trapezoid formula if necessary.
• How do you calculate the acceleration if a graph shows velocity increasing from 0 m/s to 20 m/s over 4 seconds?

  Acceleration = 5 m/s².
• How do you calculate displacement for a velocity increasing from 0 m/s to 20 m/s over 4 seconds?

  Displacement = 40 meters.
• What does a straight line with a negative slope on a velocity-time graph indicate?

  • Indicates deceleration.
  • The slope shows the rate of deceleration.
  • The area under the line represents the displacement.
• If a car slows from 25 m/s to 0 m/s over 5 seconds, what is the deceleration?

  Deceleration = -5 m/s².
• How do you calculate displacement for a car slowing from 25 m/s to 0 m/s over 5 seconds?

  Displacement = 62.5 meters.
• What does a curved line on a velocity-time graph indicate?

  • Indicates changing acceleration.
  • The slope of the tangent at any point gives the instantaneous acceleration.
  • Displacement is found by calculating the area under the curve, which may involve integration.
• What are the key features of velocity-time graphs?

  • Slope represents acceleration.
  • Positive slope = acceleration, negative slope = deceleration.
  • Area under the graph represents displacement.
  • Constant acceleration = straight line, changing acceleration = curved line.
• Why is understanding velocity-time graphs important?

  • Helps analyze the motion of objects.
  • Allows calculation of key values such as acceleration and displacement.
  • Aids in interpreting the behavior of moving objects.