Advertisements
Advertisements
प्रश्न
A block of mass 30 kg is pulled up a slope, as shown in diagram with a constant speed, by applying a force of 200 N parallel to slope.
A and B are initial and final positions of block.
(i) Calculate the work done by force in moving the block from A to B.
(ii) Calculate P.E. gained by block. [g=10ms-2]
Advertisements
उत्तर
(i) Work done in moving the block from = F × d
A to B = 200 N × 3m = 600 J
(ii) Gain in potential energy = mgh = 30 × 10 × 1.5 = 450 J.
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?
Why is a jack screw provided with a long arm?
How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.
A boy of mass m climbs up a staircase of vertical height h.
- What is the work done by the boy against the force of gravity?
- What would have been the work done if he uses a lift in climbing the same vertical height?
Give an example
Chemical energy changes to heat energy.
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.
