You didn't Provide choices to choose from. Please fix question and I'd love to be able to help.
Answer:
The potential difference between the plates is 
Explanation:
Given that,
Distance = 1.4 mm
Electric field strength 
Let the potential difference is V.
We need to calculate the potential difference between the plates
Using formula of electric field


Where, V = potential
d = distance
Put the value into the formula


Hence, The potential difference between the plates is 
Answer:
Cork
Explanation:
Cork is a solid, other ones are fluid.
Answer:
<h2>Mass of 1 Kg and 2 Kg, 1 meters apart.</h2>
Explanation:
The gravitational force is defined as

By definition, the gravitational force depends directly on the product of the masses and indirectly on the distance between the masses, which means the further they are, the less gravitational force would be. And, the greater the masses, the greater the gravitational force.
Among the options, the pair that would have the greatest gravitational force is Mass of 1 Kg and 2 Kg, with 1 meter between them.
Notice that the last choice includes the same masses but with a greater distance between them, that means it would be a weaker graviational force.
Therefore, the right answer is the second choice.
Answer:
A) if each astronaut breathes about 500 cm³, the total volume of air breathed in a year is 14716.8m³.
B) The Diameter of this spherical space station should be 30.4m
Explanation:
The breathing frequency (according to Rochester encyclopedia) is about 12-16 breath per minute. if we take the mean value (14 breath per minute), we can estimate the total breaths of a person along a year:

If we multiply this for the number of people in the station and the volume each breath needs, we obtain the volume breathed in a year.
The volume of a sphere is:

So the diameter is:
![D=2r=2\sqrt[3]{\frac{3V_{sph}}{4\pi}} =30.4m](https://tex.z-dn.net/?f=D%3D2r%3D2%5Csqrt%5B3%5D%7B%5Cfrac%7B3V_%7Bsph%7D%7D%7B4%5Cpi%7D%7D%20%3D30.4m)