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प्रश्न
State whether the following statement is True or False.
A boy does work while pushing a wall.
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उत्तर
This statement is false.
Explanation:
In physics, work is defined as force multiplied by displacement. Pushing a wall requires using force, yet the wall does not move (displacement is zero), hence the labor done is zero.
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संबंधित प्रश्न
State whether the following statement is True or False.
In an ideal machine, work done on load is equal to the work done by effort.
What is the principle on which a machine works?
Can a machine have an efficiency of 100%? Give a reason to support your answer.
Write the relation between mechanical advantage, velocity ratio and efficiency.
Give an example of the following use of a machine to change the point of application of the force.
What is the efficiency of a machine?
Classify the following as a lever, a pulley and an inclined plane:
Scissors
The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the second order.
The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the third order.
Name a machine for each of the following uses:
- to multiply the force,
- to change the point of application of force,
- to change the direction of force,
- to obtain the gain in speed.
