Advertisements
Advertisements
प्रश्न
A weight lifter lifted a load of 200 kgf to a height of 2.5 m in 5 s. Calculate:
- the work done, and
- the power developed by him. Take g = 10 N kg-1
Advertisements
उत्तर
Force= mg = 200 × 10 = 2000 N
Distance, S = 2.5m
Time , t = 5 s
(i) Work done, W= F × S
W = 2000 × 2.5m = 5000 J
(ii) Power developed = `w/t`= `5000/5` = 1000 W
APPEARS IN
संबंधित प्रश्न
When does a force perform work?
Is work a scalar or a vector quantity?
If the work done by a force in moving an object through a distance of 20 cm is 24.2 J, what is the magnitude of the force?
Give two examples of couple action in our daily life.
Fill in the boxe to show the corresponding energy transformation.
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.
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]
A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is ______.
A body of mass 0.5 kg travels on straight line path with velocity v = (3x2 + 4) m/s. The net work done by the force during its displacement from x = 0 tox = 2 m is ______.
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
