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प्रश्न
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
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उत्तर
The man moving along the slope expends more energy. It is because, while moving along the slope, he gains height and hence has extra potential energy.
संबंधित प्रश्न
What is the condition for a force to do work on a body?
Fill in the blank with suitable word :
The work done on a body moving in a circular path is __________
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.
Complete the following sentences:
Joule is the unit of .......
Give an example
Light energy changes to electrical energy.
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?
A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg−1).
