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प्रश्न
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, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.

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उत्तर
- The work done is zero because the force acts perpendicular to the displacement.
Work done at angle θ = F × s × cosθ
W = F × s × cos90∘ - The work done is positive because the object's displacement occurs in the direction of the applied force.
- The work done is negative because the object's displacement occurs in the opposite direction of the applied force.
संबंधित प्रश्न
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
A man lifts a mass of 20 kg to a height of 2.5 m. Assuming that the force of gravity on 1 kg mass is 10 N, find the work done by the man.
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
How much work is done when a body of mass m is raised to a height h above the ground?
State the SI unit of work.
Fill in the blank with suitable word :
1 joule is the work done when a force of 1 __________ moves an object through a distance of one __________ in the direction of __________.
Give one example in which a force does zero work.
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Complete the following sentences:
Joule is the unit of .......
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
