5.4.5 Velocity

• What is the definition of velocity?

  Velocity is a vector quantity that describes both the speed of an object and the direction in which it is moving.
• How does velocity differ from speed?

  Velocity specifies both the speed and the direction of an object, while speed only measures how fast something is going.
• What is the basic formula for velocity?

  Velocity = Displacement / Time
• In what units is velocity measured?

  Velocity is measured in meters per second (m/s) or kilometers per hour (km/h) with direction.
• What does displacement refer to in the context of velocity?

  Displacement is the straight-line distance between the initial and final positions of the object, with direction, measured in meters (m).
• How is time defined in the formula for velocity?

  Time is the duration over which the displacement occurs, measured in seconds (s).
• What are the key differences between speed and velocity?

  • Speed:
  • Scalar quantity (only magnitude)
  • Measures how fast an object is moving
  • No direction included
  • Velocity:
  • Vector quantity (magnitude and direction)
  • Measures how fast and in which direction an object is moving
• If a car travels 100 meters east in 20 seconds, what is its velocity?

  The velocity is 5 m/s east.
• How do you calculate the average velocity of a cyclist who travels 300 meters north and then 400 meters east in 50 seconds?

  The average velocity is 10 m/s at an angle of approximately 53.1° east of north.
• How do you calculate displacement when given two perpendicular distances?

  • Use Pythagoras' theorem:
  • Displacement = √((300 m)² + (400 m)²)
  • Resultant displacement = 500 m
• What does the slope of a velocity-time graph represent?

  The slope represents acceleration, which is the change in velocity over time.
• What does the area under a velocity-time graph represent?

  The area under the graph represents displacement.
• What is the formula for calculating average velocity?

  • Average Velocity = Total Displacement / Total Time
• If an object moves 50 meters east and then 30 meters west in 20 seconds, what is its average velocity?

  The average velocity is 1 m/s east.
• What is relative velocity?

  Relative velocity is the velocity of an object as observed from another moving object.
• If two trains are moving in the same direction with velocities of 60 km/h and 80 km/h, what is the relative velocity of the second train with respect to the first?

  The relative velocity is 20 km/h.
• What is the summary of velocity?

  • Velocity: Vector quantity that includes both speed and direction.
  • Formula: Velocity = Displacement / Time.
  • Velocity vs. Speed: Speed is scalar; velocity is vector.
  • Graphs: Velocity-time graphs show acceleration and displacement.
  • Average Velocity: Total displacement divided by total time.