Answer:
First, the meters is the unit used in almost all the world today.
Then using meters as your unit will be easier to read and interpret for a larger number of people than if you use an older system, like hands or steps.
And because of the fact that almost all the world uses the meter as the unit for length, almost all the equations and formulas are written in meters.
Precision: The meter is exactly defined as:
"The length of the path traveled by light in a vacuum in 1/299,792,458 of a second"
So the meter is an exact (and accepted) unit.
Then using this unit for measures of length also provides some "
legitimacy" for you measure.
Answer:
Mercury / Mars
Explanation:
For an object launched straight upward, the following SUVAT equation can be used

where
v is the final velocity
u is the initial velocity
g is the acceleration of gravity (free fall acceleration) (the negative sign is due to the downward direction of gravity)
h is the maximum height reached
At the maximum height, the velocity is zero, so v = 0. Re-arranging the equation,

So we see that for equal initial velocity (u), the maximum height reaches is inversely proportional to the acceleration of gravity. Therefore, the potato gun will reach the highest altitude in the planets with lowest acceleration of gravity, therefore Mercury and Mars (3.7 and 3.6 m/s^2).
The planet closest to the sun; Mercury.
Answer:

Explanation:
The electric flux through a certain surface is given by (for a uniform field):

where:
E is the magnitude of the electric field
A is the area of the surface
is the angle between the direction of the field and of the normal to the surface
In this problem, we have:
is the electric field
L = 2.0 m is the side of the sheet, so the area is

, since the electric field is perpendicular to the surface
Therefore, the electric flux is
