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प्रश्न
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उत्तर
Work done depends upon:
(i) the magnitude and direction of the applied force, and
(ii) the displacement it produces.
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संबंधित प्रश्न
A boy of mass 40 kg climbs up the stairs and reaches the roof at a height 8 m in 5 s. Calculate:
- the force of gravity acting on the boy,
- the work done by him against the force of gravity,
- the power spent by boy. (Take g = 10 m s-2)
What are the units of (a) work, and (b) energy?
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
Name the physical quantity whose SI unit is Nm.
Name the physical quantity whose MKS units are kgm2s-3.
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
State the amount of work done by an object when it moves in a circular path for one complete rotation. Give a reason to justify your answer.
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
An engine is pulling a train.
