What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.
Solution and Explanation
The satellite is moving on around the earth, displacement of the object is perpendicular to the direction of force. \(θ = 90°\).
\(W = F×s \ cos\ θ\)
\(W= F×s\ cos\ 90°\)
\(W= F×0\)
\(W= 0\)
Therefore, work done is zero.
Top Questions on Work
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- In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
- Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
• Suma is swimming in a pond.
• A donkey is carrying a load on its back.
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• A green plant is carrying out photosynthesis.
• An engine is pulling a train.
• Food grains are getting dried in the sun.
• A sailboat is moving due to wind energy. - An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?
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- Name the following.
- Tissue that forms the inner lining of our mouth.
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- Tissue that transports food in plants.
- Tissue that stores fat in our body.
- Connective tissue with a fluid matrix.
- Tissue present in the brain.
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Concepts Used:
Work
Work is the product of the component of the force in the direction of the displacement and the magnitude of this displacement.
Work Formula:
W = Force × Distance
Where,
Work (W) is equal to the force (f) time the distance.
Work Equations:
W = F d Cos θ
Where,
W = Amount of work, F = Vector of force, D = Magnitude of displacement, and θ = Angle between the vector of force and vector of displacement.
Unit of Work:
The SI unit for the work is the joule (J), and it is defined as the work done by a force of 1 Newton in moving an object for a distance of one unit meter in the direction of the force.
Work formula is used to measure the amount of work done, force, or displacement in any maths or real-life problem. It is written as in Newton meter or Nm.