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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
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
Fill in the blank with suitable word :
The work done on a body moving in a circular path is __________
How much work is done when a force of 1 N moves a body through a distance of 1 m in its own direction?
Is power a scalar quantity?
Can every force produce work?
An electric motor drives a machine which lifts a mass of 4 kg through a height of 10 m in 5 s at a constant speed. Assuming g = 10 ms-2, calculate
(i) the amount of work done, (ii) the power of the machine.
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
A ______ should act on an object.
