Acceleration

• What is meant by acceleration?

  Acceleration is the change in velocity over a given time.
• How is acceleration calculated?

  By using the equation: acceleration = change in velocity / time.
• What is the unit of acceleration?

  m/s²
• What type of quantity is velocity?

  Velocity is a vector quantity.
• What does the acceleration of an object indicate?

  It tells us the change in velocity over a given time.
• How do you calculate the acceleration of an object given its initial and final velocities and the time taken?

  • Identify the initial velocity and final velocity.
  • Calculate the change in velocity (final - initial).
  • Divide the change in velocity by the time taken.
• If a car accelerates from 15 m/s to 35 m/s in 20 seconds, what is its acceleration?


  1 m/s²
• What is the acceleration of a cyclist whose velocity reduces from 6 m/s to 0 in 12 seconds?

  -0.5 m/s²
• What does a negative acceleration indicate?

  It indicates that the object is decelerating.
• What does the gradient of a velocity-time graph represent?

  • The gradient represents the acceleration of the object.
  • A horizontal line indicates constant velocity.
  • An upward slope indicates acceleration.
  • A downward slope indicates deceleration.
• How do you calculate acceleration from a velocity-time graph?

  Subtract the initial velocity from the final velocity and divide by time.
• What does the area under a velocity-time graph represent?

  The area represents the distance traveled or displacement.
• How do you calculate the total distance traveled from a velocity-time graph with constant acceleration or deceleration?

  • Divide the graph into shapes (triangles, rectangles).
  • Calculate the area of each shape.
  • Add the areas together for total distance or displacement.
• If a velocity-time graph shows non-constant acceleration, how can you estimate the total area under the graph?

  Count squares and estimate the area of partial squares.
• What is the total distance traveled if there are 20 squares under a velocity-time graph, each with an area of 250?

  5,000 m
• What should you be able to calculate by the end of the video?

  Velocity of an object accelerating at a constant rate
• What should you be able to describe by the end of the video?

  Acceleration of an object falling through a fluid
• How is acceleration calculated?

  By using the equation: acceleration = change in velocity / time
• What is the equation for calculating distance when an object is accelerating at a constant rate?

  • Final velocity squared - Initial velocity squared = 2 × Acceleration × Distance
• What is provided in the exam regarding the equation for distance?

  Students are given the equation in the exam.
• Which tier of students is more likely to encounter the distance equation in the exam?

  Higher tier students are more likely to encounter it.
• What is the initial velocity of the car in the sample question?

  8 meters per second
• What is the final velocity of the car in the sample question?

  12 meters per second
• What is the acceleration of the car in the sample question?

  2 meters per second squared
• What is the distance traveled by the car in the sample question?

  20 meters
• What is the initial velocity of the cyclist in the question?

  3 meters per second
• What is the final velocity of the cyclist in the question?

  5 meters per second
• What is the distance traveled by the cyclist in the question?

  50 meters
• What is the acceleration of the cyclist in the question?

  0.16 meters per second squared
• What is the initial velocity of the train in the final question?

  20 meters per second
• What is the acceleration of the train in the final question?

  5 meters per second squared
• What is the distance traveled by the train in the final question?

  50 meters
• What is the final velocity of the train in the final question?

  30 meters per second
• What is the acceleration of an object falling towards the Earth?

  Approximately 9.8 meters per second squared
• What force acts against a skydiver as they fall?

  Air resistance
• What happens when the force of air resistance balances the force due to gravity?

  The object stops accelerating and moves at a constant velocity.
• What is the term used for the constant velocity reached by a falling object?

  Terminal velocity
• What does the terminal velocity depend on?

  It depends on the object and its shape.
• What are the key points about acceleration in the context of falling objects?

  • Initially accelerates at around 9.8 m/s² due to gravity
  • Air resistance acts against the fall
  • Reaches terminal velocity when forces balance