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संबंधित प्रश्न
Name a common device where a gear train is used
State the S.I. unit of work and define it.
What are the two kinds of mechanical energy?
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
A person of mass 50 kg climbs a tower of height 72 metres. Calculate the work done. (g = 9.8 m s−2).
How much work is done when a force of 2 N moves a body through a distance of 10 cm in the direction of force?
What happens to the work done when the dispacement of body is at right angles to the direction of force acting on it? Explain your answer.
Write an expression for work done by a force depends?
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
List any six forms of energy and write a short note on each of them.
Fill in the boxe to show the corresponding energy transformation.
Fill in the boxe to show the corresponding energy transformation.
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
The work done by the heart is 1 Joule per beat. Calculate the power of the heart if it beats 72 times in one
One labourer carried four pans of road metal through a distance of 100 metres. If he carries two pans of road metal through a 200 metre distance ______ work will be done.
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
