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प्रश्न
Is the motion of moon around the earth in circular path an accelerated motion?
उत्तर
Yes, it is an accelerated motion.
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संबंधित प्रश्न
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?
No work is done by a force if the body
State two factors on which the work done on a body depends.
Define 1 joule of energy.
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The loss in potential energy of the body,
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
The work done on an object does not depend on the :
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 :
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
Name the physical quantity associated with the 'rate of doing work'.
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
Light energy changes to electrical energy.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
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.
An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water. Calculate the work done on the water in one minute.
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.
