1.4 Reference Frames and Relative Motion

• What is a reference frame?

  A coordinate system
• Match the reference frame with its description:

  Train ↔️ Origin: Inside the train ||| Orientation of Axes: Parallel to train tracks

  Ground ↔️ Origin: Fixed location on ground ||| Orientation of Axes: Aligned with map directions
• Objects in an inertial frame follow Newton's laws of motion.


  True
• A non-inertial reference frame is a reference frame that is accelerating.
• Match the property with the type of reference frame:

  Acceleration = 0 ↔️ Inertial Reference Frame

  Additional forces present ↔️ Non-inertial Reference Frame
• How is relative velocity calculated between two objects in different reference frames?

  Add or subtract velocities
• What is the formula for calculating relative velocity using vector addition?

  Velocity of Object - Velocity of Observer's Reference Frame
• Vector addition is used to calculate relative velocity between different reference frames.


  True
• If an object is moving at 20 m/s east in the ground reference frame, and the observer is moving at 10 m/s west in the train reference frame, what is the relative velocity of the object with respect to the train?

  30 m/s east
• A reference frame provides a consistent basis for determining position and velocity.
• Inertial reference frames are accelerating.

  False
• Give an example of an inertial reference frame.

  Stationary observer on Earth
• Relative velocity is calculated using the formula: Vobj - Vobs, where Vobs is the velocity of the observer.
• Steps for calculating relative velocity using vector addition

  1️⃣ Identify the velocities of the objects and reference frames

  2️⃣ Convert velocities to vectors with components

  3️⃣ Add the velocity components: Relative velocity = Vobj - Vobs
• To calculate relative velocity, vector addition is used.
• What are some applications of reference frames and relative motion?

  Navigation, sports, weather forecasting
• There are two main types of reference frames: inertial and non-inertial.


  True
• Relative velocity is the velocity of an object with respect to an observer in a different reference frame.
• An inertial reference frame is a reference frame that is not accelerating.
• What is an example of an inertial reference frame?

  Stationary frame on Earth
• Objects in a non-inertial frame do not follow Newton's laws of motion.

  True
• Relative velocity is the velocity of an object with respect to an observer in a different reference frame.
• Vector addition is used to find relative velocity between two objects in different reference frames.


  True
• What is the relative velocity of an object moving at 20 m/s east with respect to a train moving at 10 m/s west?

  30 m/s east
• The relative velocity between two objects in different reference frames is calculated using vector addition
• A reference frame consists of an origin and a set of axes.


  True
• What are the two main types of reference frames?

  Inertial and non-inertial
• In non-inertial reference frames, Newton's laws require considering additional forces such as centrifugal or Coriolis force.
• Give an example of a non-inertial reference frame.

  Observer in accelerating car
• Match the reference frame type with its property:

  Inertial Reference Frame ↔️ Acceleration is 0

  Non-inertial Reference Frame ↔️ Newton's laws require additional forces
• If Car A is moving at 20 m/s east and Car B is moving at 10 m/s east, what is the relative velocity of Car A with respect to Car B?

  10 m/s east
• Vector addition for relative velocities involves converting velocities to vectors with components.


  True
• If Car A is moving at (10, 0) m/s on the ground and Car B is moving at (5, 0) m/s, what is the relative velocity of Car A with respect to Car B?

  (5, 0) m/s
• Vector addition is essential for solving problems involving relative motion between objects in different reference frames.

  True