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प्रश्न
उत्तर
1 H.P. = 0.746 kW
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संबंधित प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A sailboat is moving due to wind energy.
A coolie is moving on a road with a luggage on his head. Does he perform work against the force of gravity? Give reason for your answer.
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.
Name the forms of energy which a wound-up watch spring possesses.
A box of weight 150 kgf has gravitational potential energy stored in it equal to 14700 J. Find the height of the box above the ground. (Take g = 9.8 N kg-1)
State the law of conservation of energy.
How much work is done when a force of 2 N moves a body through a distance of 10 cm in the direction of force?
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Give two examples of couple action in our daily life.
On what factors does the work done by a force depend?
Write an expression for work done by a force depends?
A body does 20 J of work in 10 s. What is its power?
An electric motor drives a machine which lifts a mass of 4 kg through a height of 10 m in 5 s at a constant speed. Assuming g = 10 ms-2, calculate
(i) the amount of work done, (ii) the power of the machine.
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
State the energy changes which take place when A toy car with a wound spring moves on ground.
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.
