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प्रश्न
उत्तर
1 H.P. = 0.746 kW
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संबंधित प्रश्न
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
A water pump raises 50 litres of water through a height of 25 m in 5 s. Calculate the power of the pump required.
(Take g = 10 N kg-1 and density of water = 1000 kg m-3)
A car is running at a speed of 15 km h-1 while another similar car is moving at a speed of 45 km h-1. Find the ratio of their kinetic energies.
What do you mean by degradation of energy?
State the SI unit of work.
Is work a scalar or a vector quantity?
If the work done by a force in moving an object through a distance of 20 cm is 24.2 J, what is the magnitude of the force?
A max X goes to the top of a building by a vertical spiral staircase. Another man Y of the same mass goes to the top of the same building by a slanting ladder. Which of the two does more work against gravity and why?
Name five appliances or machines which use an electric motor.
A body does 20 J of work in 10 s. What is its power?
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
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.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
