
The rate of change of velocity per unit time is called acceleration.
Its SI unit is m/s².

Answer:
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
Explanation:
Initial total energy = final total energy
PE₁ + KE₁ = PE₂ + KE₂
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
International system of units
Answer: 27.21 V
Explanation:
The <u>electric potential</u>
due to a point charge is expressed as:

Where:
is the <u>electric constant</u>
is the <u>electric charge of the hydrogen nucleus</u>, which is positive
is the <u>distance</u>
Rewritting the equation with the known values:

Finally:
Well the trivial answer is zero, since there is indeed a "zero vector". Assuming you aren't allowed to use the zero vector you would need at least two. They would be antiparallel and of equal magnitude. (That is be pointing in opposite directions and have the same length)