Answer:
We have to show surface area 
,with few conditions that is by considering Force 
and Pressure 
to be respectively.
Explanation:
The atmospheric pressure is 
on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is 
.
Now to calculate surface area we can find it from 
and re-arranging it to.
So plugging the values,
Surface area 
Hence from the above calculations we can say that surface area is 
.
So the surface area of an average person can be said to have , using the concept of pressure and force.
Answer:
She will make the mass of the smiley face twice as massive in order to keep the mobile in perfect balance.
Explanation:
mass of an object is directly proportional to the cube of its length. In this case the length is constant, the mass will also be constant for the smiley face, so that the mobile will be kept in perfect balance.
Therefore, If Anya decides to make the star twice as massive, and not change the length of any crossbar or the location of any object, she will make the mass of the smiley face twice as massive in order to keep the mobile in perfect balance.
Answer: to provide evidence to a theory
Explanation: Experimentation allows for multiple trials to provide evidence to a scientific theory. Without experimentation there would be no data to back up your hypothesis.
Answer:
b. 
Explanation:
As we know that the electric field due to infinite line charge is given as
here we can find potential difference between two points using the relation
now we have
now we have
now plug in all values in it
now we know by energy conservation
