Answer:
6.86 m/s
Explanation:
velocity of the gasoline through the hole would be

As the height would decrease, the velocity of the flow would decrease.
If the lid of the tank would be closed, the pressure would reduce. so, again the velocity of the flow would reduce.
Answer:
A) Object A is 3.25 times hotter.
B) Object A radiates 111.6 times more energy per unit of area.
Explanation:
Wiens's law states that there is an inverse relationship between the wavelength in which there is a peak in the emission of a black body and its temperature, mathematically,
,
where
is the temperature in kelvins and,
is the wavelenght (in meters) where the emission is in its peak.
From here, if we solve Wien's law for the temperature we get
.
Now, we can easily compute the temperatures.
For object A:

.
For object B:


From this, we get that
,
which means that object A is 3.25 times hotter.
Stefan's Law states that a black body emits thermal radiation with power proportional to the fourth power of its temperature.
This is
,
where
is call the Stefan-Boltzmann constant.
From this, power can be easily compute:
,
and we can notice that
,
which means that object A radiates 111.6 time more energy per unit of area.
Suppose earth is a soid sphere which will attract the body towards its centre.So, acc. to law of gravitation force on the body will be,
F=G*m1m2/R^2
but we now that F=ma
and here accleration(a)=accleration due to gravity(g),so
force applied by earth on will also be mg
replace above F in formula by mg and solve,
F=G*mE*m/R^2 ( here mE is mass of earth and m is mass of body)
mg=G*mEm/R^2
so,
g =G*mE/R^2
c adding research resources during an investigation