Question

14. There is a four storeyed house in the neighbourhood of Rohan and Amit which has
two types of staircases in it. One is a normal, slanting type staircase which is inside
the house and the other one is a spiral type (vertical) staircase at the back side of
the house. Both the staircases lead from the ground floor to the roof of the house.
Rohan and Amit are both students of class IX in different schools. Incidentally, they
are both of the same weight. Rohan said that a person using slanting staircase inside
the house would do more work against a certain 'natural force' in going from ground
floor to the roof of the house (because the distance moved by the person in using the
slanting staircase is more). Rohan also said that the work done by the same person
against the same natural force in going from ground floor to roof of the house would
be less by using the spiral type (vertical) staircase (because the distance moved by
him in this case will be less). Amit, however, did not agree with Rohan. Amit said
that whether this person uses slanting staircase or spiral type (vertical) staircase,
work done by him against the natural force in going from ground floor to roof of the
house would be the same. Rohan then decided to go from the ground floor to the
roof top by slanting staircase and took 90 seconds for doing this job. On the other
hand, Amit went from ground floor to the roof top by spiral type (vertical) staircase
and took 2 minutes for this job.
(a) Name the natural force against which work has to be done in going from
ground floor to the roof top of the house.
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(b) What supplies energy for doing work when Rohan and Amit climb up to the
roof of the house?
(c) Whose statement about the amount of work done against the natural force in
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going from ground floor to roof top is correct and why?
(d) Who has more power in terms of physics in climbing to roof top : Rohan or

Amit ? Why?
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Answer 1

Answer:

a) gravitational force

b) the body supplies energy

c) don't know the answer

d) rohan