Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
Solution and Explanation
According to Newton's first law of motion, an object will remain at rest or in uniform motion unless acted upon by a net external force. In the absence of any external force, an object at rest will stay at rest, and an object in motion will continue moving at a constant velocity. However, internal forces like friction or air resistance could still cause displacement.
So, while external forces are necessary for changes in motion, internal forces can lead to displacement even without an external force.
Top Questions on Work
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Questions Asked in CBSE Class IX exam
(Street Plan) : A city has two main roads which cross each other at the centre of the city. These two roads are along the North-South direction and East-West direction.
All the other streets of the city run parallel to these roads and are 200 m apart. There are 5 streets in each direction. Using 1cm = 200 m, draw a model of the city on your notebook. Represent the roads/streets by single lines. There are many cross- streets in your model. A particular cross-street is made by two streets, one running in the North - South direction and another in the East - West direction. Each cross street is referred to in the following manner : If the 2nd street running in the North - South direction and 5th in the East - West direction meet at some crossing, then we will call this cross-street (2, 5). Using this convention, find:
(i) how many cross - streets can be referred to as (4, 3).
(ii) how many cross - streets can be referred to as (3, 4).
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- Discuss what these phrases mean to you.
(i) a yellow wood
(ii) it was grassy and wanted wear
(iii) the passing there
(iv) leaves no step had trodden black
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- Do you think Innisfree is only a place, or a state of mind? Does the poet actually miss the place of his boyhood days?
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- A truly beautiful mind
- Did Margie have regular days and hours for school? If so, why?
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- The fun they had
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.