Answer:

Explanation:
The formula for potential energy is:

where <em>m </em>is the mass, <em>g</em> is the gravitational acceleration, and <em>h</em> is the height.
The mass of the book is 0.4 kilograms. The gravitational acceleration on Earth is 9.8 m/s². The height of the book is 2 meters.

Substitute the values into the formula.

Multiply the first two numbers.
- 0.4 kg*9.8 m/s²= 3.92 kg*m/s²
- If we convert the units now, the problem will be much easier later on.
- 1 kg*m/s² is equal to 1 Newton. So, our answer of 3.92 kg*m/s² is equal to 3.92 N

Multiply.
- 3.92 N* 2 m=7.84 N*m
- 1 Newton meter is equal to 1 Joule (this is why we converted the units).
- Our answer is equal to<u> 7.84 Joules.</u>

<span>It is important to use the Système Internationale (SI) units to describe motion, and other scientific concepts, firstly because the units are the most widely used. Unit choice is largely arbitrary, however, because many scientific units are derived from the base SI units, for example, the Newton is kg m s-2. Thus, secondly, more complex units are based on the bedrock of the SI units.</span>
Answer:
115799.256V/m
Explanation:
Given V = 623v, d = 5.38mm = 0.00538m
Strength of electric field E = V/d
E = 623/0.00538
= 115799.256V/m