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 boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
A box of weight 150 kgf has gravitational potential energy stored in it equal to 14700 J. Find the height of the box above the ground. (Take g = 9.8 N kg-1)
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 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
Define Translational motion.
How long should an electric motor, of power 2 H.P. operate, so as to pump 5 m3 of water from a depth of 15m. [Take g = 10 N kg−1]
What is work?
