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प्रश्न
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
विकल्प
Yes
No
उत्तर
No
संबंधित प्रश्न
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (see the given figure). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?
Power spent by a body depends on the time for which it does work.
Write the expression for work done by a force.
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?
State two disadvantages of producing hydroelectricity.
Fill in the blank with suitable word :
The work done on a body moving in a circular path is __________
In which of the following case the work done by a force will be maximum : when the angle between the direction of force and direction of motion is 0° or 90°?
What is the relationship between Nm and dyne cm?
A boy does work when he pushes against a brick wall. (yes/no).
Can every force produce work?
Distinguish between work and power.
Name the physical quantity whose MKS units are kgm2s-3.
Define the term work. Name the CGS and SI unit of work.
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
Calculate the work done when:
A 5 kg weight is lifted 10 m vertically. (g = 9.8 m/s2)
What is power? How do you differentiate kilowatt from kilowatt-hour? The Jog Falls in Karnataka state are nearly 20 m high. 2000 tonnes of waterfalls from it in a minute. Calculate the equivalent power if all this energy can be utilized? (g = 10 m s–2)
