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प्रश्न
Draw a neat labeled diagram to show the direction of two forces acting on a body to produce rotation in it. Also mark the point about which rotation takes place.
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संबंधित प्रश्न
Work done by a boy depends on the time in which he does work.
State the S.I. unit of work and define it.
What are the two kinds of mechanical energy?
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
P, Q and R are three forces which act as shown in fig.
The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
A cricket ball is thrown up from the earth's surface. What happens to its P.E.
(a) during the motion
(b) at the highest point?
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Define the term work. Name the CGS and SI unit of work.
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
Fill in the boxe to show the corresponding energy transformation.
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
Chemical energy changes to heat energy.
In the following case write yes, if the work is being done and no if no work is being done.
A coolie standing with a heavy load on his head
Force acting on a particle moving in a straight line varies with the velocity of the particle v as F = `K/v`, where K is a constant. The work done by this force in time t is
Work done by this force at any instant is ______.
