Motion In Straight Line

Question

A body of mass m is taken from distance r₁ to r₂ from the centre of the earth. What is the work required to displace the body?

Solution

The force acting on mass m when at a distance r from the centre of the earth is,

straight F equals GMm over straight r squared

This force must be applied in the upward direction, to displace the body in upward direction.
If the body is displaced by a small distance 'dr' then work done is,

space dW equals GMm over straight r squared dr

Total work done in displacing the body from r₁ to r₂ is,

dW equals integral subscript straight r subscript 1 end subscript superscript straight r subscript 2 end superscript GMm over straight r squared dr equals open square brackets negative GMm over straight r close square brackets subscript straight r subscript 1 end subscript superscript straight r subscript 2 end superscript

equals GMm open square brackets 1 over straight r subscript 1 minus 1 over straight r subscript 2 close square brackets

, is the amount of work required to displace the body.

Some More Questions From Motion in Straight Line Chapter

Can a body be in motion in the frame associated with the body itself?

When an object in motion can be considered as particle or point object?

Can you think of physical phenomena involving the moon in which moon cannot be treated as particle?

A train is crossing the bridge. Can it be taken as a particle?

Can a train be taken a particle? Give an example in support of your answer.

A particle is moving along curved line in space. Is the motion one dimensional?

State which of the following are examples of one, two or three dimensional motion:

(a) A kite flying in the sky.

(b) The earth revolving around the sun.

(c) A train moving along the equator of the earth in clockwise direction.

(d) Accelerated motion of a particle in a straight line.

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Motion In Straight Line

A body of mass m is taken from distance r₁ to r₂ from the centre of the earth. What is the work required to displace the body?

Some More Questions From Motion in Straight Line Chapter

Can a body be in motion in the frame associated with the body itself?

When an object in motion can be considered as particle or point object?

Can you think of physical phenomena involving the moon in which moon cannot be treated as particle?

A train is crossing the bridge. Can it be taken as a particle?

Can a train be taken a particle? Give an example in support of your answer.

A particle is moving along curved line in space. Is the motion one dimensional?

State which of the following are examples of one, two or three dimensional motion:

(a) A kite flying in the sky.

(b) The earth revolving around the sun.

(c) A train moving along the equator of the earth in clockwise direction.

(d) Accelerated motion of a particle in a straight line.

Define distance.

Define displacement.

Can magnitude of displacement be greater than distance travelled by particle?

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For Daily Free Study Material Join wiredfaculty

Motion In Straight Line

A body of mass m is taken from distance r1 to r2 from the centre of the earth. What is the work required to displace the body?

Some More Questions From Motion in Straight Line Chapter

Can a body be in motion in the frame associated with the body itself?

When an object in motion can be considered as particle or point object?

Can you think of physical phenomena involving the moon in which moon cannot be treated as particle?

A train is crossing the bridge. Can it be taken as a particle?

Can a train be taken a particle? Give an example in support of your answer.

A particle is moving along curved line in space. Is the motion one dimensional?

State which of the following are examples of one, two or three dimensional motion: (a) A kite flying in the sky. (b) The earth revolving around the sun. (c) A train moving along the equator of the earth in clockwise direction. (d) Accelerated motion of a particle in a straight line.

Define distance.

Define displacement.

Can magnitude of displacement be greater than distance travelled by particle?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

A body of mass m is taken from distance r₁ to r₂ from the centre of the earth. What is the work required to displace the body?

State which of the following are examples of one, two or three dimensional motion:

(a) A kite flying in the sky.

(b) The earth revolving around the sun.

(c) A train moving along the equator of the earth in clockwise direction.

(d) Accelerated motion of a particle in a straight line.