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Define the term calorie. How is it related to joule (the S.I. unit of heat)?
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Define one kilo-calorie of heat.
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A bullet of mass 0.5 kg slows down from a speed of 5 m s-1 to that of 3 m s-1. Calculate the change in kinetic energy of the ball.
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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?
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State two advantage of producing hydroelectricity.
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State two disadvantages of producing hydroelectricity.
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State the energy transformation on the following:
Electricity is obtained from solar energy.
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State the law of conservation of energy.
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What do you mean by degradation of energy?
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Explain degradation of energy by taking two examples of your daily life.
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The diagram below shows a claw hammer used to remove a nail :

(i) To which class of lever does it belong ?
(ii) Give one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one.
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Its moment of a force scalar or a vector quantity?
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Name the physical quantity whose SI unit is Nm.
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What is meant by a translational motion? Give one example.
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What is the relationship between Nm and dyne cm?
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Why does a spanner have a long handle?
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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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Give two examples of couple action in our daily life.
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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.
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