A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force is greatest
Gravitational force is the attractive force between two masses due to their mass and distance. It is described by Newton’s law of universal gravitation which states that the force is directly proportional to the product of the masses and inversely proportional to the square of the distance between them.
Class 11 Physics Chapter 5 Work, Energy and Power explains the fundamental concepts of work energy and power focusing on their definitions and relationships. It discusses types of energy including kinetic and potential energy explores the conservation of energy principle and provides real-life applications to aid understanding for CBSE EXAM 2024-25.
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When a body is projected vertically from the Earth and reaches a height equal to the Earth’s radius before returning, we can analyze the power exerted by the gravitational force throughout its motion. The gravitational force acts as a constant downward force, affecting the body’s velocity as it rises and falls.
Initially, at the moment just after the body is projected, it has its maximum velocity, resulting in a certain amount of kinetic energy. As the body ascends, gravity does negative work on it, causing its velocity to decrease until it reaches its maximum height, where the velocity becomes zero. At this point, the power exerted by the gravitational force is also zero, as power is the product of force and velocity.
As the body starts descending, it accelerates due to gravity, and its velocity increases. Just before the body hits the Earth, it reaches its maximum velocity once again. The gravitational force, although constant, does more work as the velocity of the body increases. Therefore, the power exerted by the gravitational force is greatest at the instant just before the body strikes the Earth, as both the gravitational force and the velocity are at their maximum values at that point.
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