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प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Suma is swimming in a pond.
उत्तर
Suma is moving forward while swimming by applying force in a particular direction and is getting displaced in the direction of force hence, work is being done.
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संबंधित प्रश्न
Define 1 J of work.
Define 1 joule of energy.
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)
How much energy is gained by a box of mass 20 kg when a man, carrying the box waits for 5 minutes for a bus?
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
A force of 50 N acts on a body and moves it a distance of 4 m on horizontal surface. Calculate the work done if the direction of force is at an angle of 60° to the horizontal surface.
In case of negative work, the angle between the force and displacement is :
A girl weighing 400 N climbs a vertical ladder. If the value of g be 10 m s−2, the work by her after climbing 2 m will be :
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
Name the physical quantity associated with the 'rate of doing work'.
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
Define energy and state the unit of energy and the law of conservation of energy.
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
Give an example
Electrical energy changes to heat energy.
