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NEET PHYSICSLAWS OF MOTIONEasy

Question

Rocket engines lift a rocket from the earth surface because hot gases with high velocity:

A

push against the earth.

B

push against the air.

C

react against the rocket and push it up.

D

heat up the air which lifts the rocket.

Step-by-Step Solution

  1. Principle: Rocket propulsion is based on Newton's Third Law of Motion ('To every action, there is always an equal and opposite reaction') and the Law of Conservation of Momentum [Source 60, 61].
  2. Mechanism: The rocket engine exerts a large force on the hot gases to eject them backwards at high velocity (Action). As a reaction, the escaping gases exert an equal and opposite force (Thrust) on the rocket in the forward (upward) direction.
  3. Misconceptions: Rockets do not need air or the Earth's surface to push against; they function efficiently in the vacuum of space where there is no air or ground. Therefore, options suggesting pushing against air or earth are incorrect [Source 55, 60].

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from LAWS OF MOTION. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSLAWS OF MOTIONrocketenginesrocketsurfacebecause

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