Answer:a
Explanation:
We have to lift the load two loads up one story, so energy required is
let m be the mass of each load and h is the height of each story
Energy
Here energy gained is the potential energy which depends upon the datum(floor).
For lifting one load up one story
Energy required
thus is half of
So option a is correct
Answer:
the liquid has less height than the mercury
h_{ liquid} =
Explanation:
The pressure as a function of the height is given by
P = ρ g h
where ρ is the density of the liquid, g the acceleration of gravity and h the height reached by the column of the liquid
In that case they say that the pressure is the standard one that is P = 1.01 10⁵ Pa = 760 mmHg
The first way to give the pressure is in SI units and the second way is the height that the mercury column reaches
In the case of building a barometer with a liquid that has a density greater than that of mercury
ρ_liquid > ρ_Hg
the pressure
P =ρ_lquid g h_liquid
if we have the same pressure
ρ_{Hg} g h_{Hg} = ρ_{liquid} g h_{liquid}
h_{ liquid} =
therefore the liquid has less height than the mercury