Advertisements
Advertisements
प्रश्न
A boy weighing 25 kgf climbs up from the first floor at height 3 m above the ground to the third floor at height 9m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg -1)
उत्तर
Force of gravity on boy = mg = 25 × 10 = 250N
Increase in gravitational potential energy = Mg (h2-h1)
= 250 × (9−3)
=250 × 6 = 1500 J
APPEARS IN
संबंधित प्रश्न
What is the work done by the moon when it revolves around the earth?
A coolie does no work against the force of gravity while carrying a luggage on a road.
The energy of a body is its capacity to do .........
Write the expression for work done by a force.
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
1 J = ______ calorie.
Differentiate between energy and power.
State the SI unit of work.
Does the earth move around the sun with a uniform velocity?
Define 'joule'.
What is the ratio of SI units to CGS units of 'work'?
Give an example
Light energy changes to electrical energy.
In the following case write yes, if the work is being done and no if no work is being done.
A boy climbing up a staircase.
Why is less effort needed to lift a load over an inclined plane as compared to lifting the load directly?
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]
The work done by the heart is 1 Joule per beat. Calculate the power of the heart if it beats 72 times in one
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).
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
