An inertial frame of reference is a frame in which Newton's first law of motion holds true: an object at rest stays at rest, and an object in motion stays in motion with constant velocity, unless acted upon by a net force. Essentially, an inertial frame is one that is not accelerating.Let's analyze the options: A) A passenger in a train which is slowing down to a stop: The train is decelerating, which is a form of acceleration. The frame of reference of the passenger is non-inertial. You would feel a force pushing you forward even if no real force is acting on you relative to the train. B) A driver in a car moving with a constant velocity: Constant velocity means zero acceleration. The frame of reference of the driver (relative to the road) is inertial. C) A pilot in an aircraft which is taking off: The aircraft is accelerating (increasing speed and/or changing direction upwards). The frame of reference of the pilot is non-inertial. You would feel pushed back into your seat. D) A child revolving in a merry-go- round: Revolving in a circle involves a change in the direction of velocity, meaning there is acceleration (centripetal acceleration). The frame of reference of the child is non-inertial. You would feel a force pushing you outwards (centrifugal force, which is a fictitious force in the non-inertial frame).
Which of the following observations are inertial?
Asked in TNPSC CS Prelims 2024 · Topic: Mechanics (Newton's Laws of Motion and their applications)
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Answer: B. A driver in a car moving with a constant velo‐ city
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