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A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]
- a)at the highest position of the body
- b)at the instant just before the body hits the earth
- c)it remains constant all through
- d)at the instant just after the body is projected
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
A body projected ver tically fr om the ear th reaches a height equal t...
Power exerted by a force is given by P = F.v
When the body is just above the earth’s surface, its velocity is greatest. At this instant, gravitational force is also maximum.
Hence, the power exerted by the gravitational force is greatest at the instant just before the body hits the earth.
When the body is just above the earth’s surface, its velocity is greatest. At this instant, gravitational force is also maximum.
Hence, the power exerted by the gravitational force is greatest at the instant just before the body hits the earth.
Most Upvoted Answer
A body projected ver tically fr om the ear th reaches a height equal t...
**Answer:**
The power exerted by the gravitational force can be calculated using the formula:
Power = force x velocity
When a body is projected vertically upwards, the only force acting on it is the gravitational force. The gravitational force is given by:
F = mg
Where:
F = gravitational force
m = mass of the body
g = acceleration due to gravity
Since the body reaches a height equal to the Earth's radius, the distance traveled by the body is 2 times the Earth's radius. Let's assume the Earth's radius is R.
Therefore, the work done against the gravitational force is given by:
Work = force x distance
= mg x 2R
= 2mgR
Now, the time taken to reach the maximum height is given by:
t = (2u sinθ) / g
Where:
t = time taken
u = initial velocity
θ = angle of projection
g = acceleration due to gravity
Since the body is projected vertically upwards, the angle of projection is 90° and the sine of 90° is 1.
Therefore, the time taken to reach the maximum height is:
t = (2u) / g
Now, the power exerted by the gravitational force can be calculated using the formula:
Power = Work / time
= (2mgR) / [(2u) / g]
= mg^2R/u
From this equation, we can see that the power exerted by the gravitational force is inversely proportional to the initial velocity (u). As the body reaches the highest position, the velocity becomes zero. Therefore, the power exerted by the gravitational force is greatest at the highest position of the body.
Hence, the correct answer is option 'A' - at the highest position of the body.
The power exerted by the gravitational force can be calculated using the formula:
Power = force x velocity
When a body is projected vertically upwards, the only force acting on it is the gravitational force. The gravitational force is given by:
F = mg
Where:
F = gravitational force
m = mass of the body
g = acceleration due to gravity
Since the body reaches a height equal to the Earth's radius, the distance traveled by the body is 2 times the Earth's radius. Let's assume the Earth's radius is R.
Therefore, the work done against the gravitational force is given by:
Work = force x distance
= mg x 2R
= 2mgR
Now, the time taken to reach the maximum height is given by:
t = (2u sinθ) / g
Where:
t = time taken
u = initial velocity
θ = angle of projection
g = acceleration due to gravity
Since the body is projected vertically upwards, the angle of projection is 90° and the sine of 90° is 1.
Therefore, the time taken to reach the maximum height is:
t = (2u) / g
Now, the power exerted by the gravitational force can be calculated using the formula:
Power = Work / time
= (2mgR) / [(2u) / g]
= mg^2R/u
From this equation, we can see that the power exerted by the gravitational force is inversely proportional to the initial velocity (u). As the body reaches the highest position, the velocity becomes zero. Therefore, the power exerted by the gravitational force is greatest at the highest position of the body.
Hence, the correct answer is option 'A' - at the highest position of the body.
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Community Answer
A body projected ver tically fr om the ear th reaches a height equal t...
The expression for acceleration due to gravity is
, if
. increasing as r increases.
, if
. decreases as r increses.
, if
so the expression will have highest value at surface. i.e.
answer is option C.
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A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? for NEET 2025 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer?.
A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? for NEET 2025 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer?.
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A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of A body projected ver tically fr om the ear th reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest [2011]a)at the highest position of the bodyb)at the instant just before the body hits the earthc)it remains constant all throughd)at the instant just after the body is projectedCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
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